engine light Options

[celicaboston1983]

My engine light has been on for two yrs now I believe it was the egr code. And I'm probley not gonna bother fixing it. I was just wondering if there anything I can do to disable the check engine light like pull a fuse or bulb I need my inspection sticket done soon.

[bindertch]

You are going to want to get that checked because the EGR has a big part in emisions. Also it is a check to see if the CEL even lights and can fail a car if it doesn't. What year is your celica and we can help you get the codes and give some advice on how to get it fixed.

[hurley97]

if you have a 96+ with OBDII they're just going to plug the scanner into the car and the codes will come up anyway. and if you have a 94-95 with OBDI they probably just use the sniffer (I guess) and if its your EGR valve then you'll most likely fail emissions anyway, it won't matter if the bulb works or not

and I believe the fuse for that controls all the gauge lights

[celicaboston1983]

its a 94gt lights been on for 2 or 3 yrs years now. ive been bribing the guy at this shop I go to but my brother went a couple of weeks ago and said they dont do it no more. well I brought it to the shop like 2 yrs ago changed the egr with three different one light still on then they cleaned throttle I believe and still on. Last time I ran emissions I was still below the allowed amount I just can't pass because the stupid light is on.

[hurley97]

ever reset the ECU after changing the EGR? pull the EFI fuse and see if it goes off. if not I guess pull the bulb

[celicaboston1983]

i didnt do it the people at the shop did it. not sure if I ever saw them pull a fuse im gonna assume no. where is the efi fuse?

[6strngs]

i didnt do it the people at the shop did it. not sure if I ever saw them pull a fuse im gonna assume no. where is the efi fuse?

in your fuse box under your hood.

my car has the CEL too. I've pulled the EGR off twice and cleaned everything out both times, pulled the fuses, and it makes the light go off for a little while then it comes back on. I need my car smogged before next month, so I just ordered a new EGR and vaccuum module and I'm hoping it'll be fixed after that. if not, my guess is the sensor is faulty or something...

[celicaboston1983]

i guess im in the same boat as you I just gave up after going to the shop like 20 times for the same damn thing. the shop told me to go to the dealer. The longest I got the light off was about 3-4 hrs. Throw some ideals at me guys I have 3 weeks lefted.

[6strngs]

i guess im in the same boat as you I just gave up after going to the shop like 20 times for the same damn thing. the shop told me to go to the dealer. The longest I got the light off was about 3-4 hrs. Throw some ideals at me guys I have 3 weeks lefted.

the thing is, if they tried three different EGRs on there but didn't reset the computer (by pulling the EFI fuse) it could cause the CEL to stay on even if the problem was fixed. what needs to be done is after the new EGR goes on, reset the computer, there should be no CEL when you start the car, and if it doesn't come on again after the computer has relearned everything (I think it's supposed to be like 50 miles of driving.) then your problem is fixed.

I'll let you know how it works out for me with the new EGR and vacuum module.

[56willysnut]

Clear computer, then drive car to emissions station, do not shut it off. CEL illuminates after second drive cycle. If you get it tested during first drive cycle your good to go.

[celicaboston1983]

thats what i did the light came back one right after i was done.

[6strngs]

thats what i did the light came back one right after i was done.

did it pass? how high was your NOx?

Btw, I recieved my new EGR today, I should be putting it on tomorrow so I'll let you know if it fixes my problem.

This post has been edited by 6strngs: Mar 9, 2007 - 12:22 AM

[6strngs]

ok, so today I put on a new EGR valve, vacuum module, and a new sensor (the one that plugs into the EGR valve). I pulled out the ECU and EFI fuses for aprox. 30 seconds, then put them back in. I've started the car 3-4 times, but haven't driven it very far yet. so far no check engine light though, so if it really does come on during the second drive cycle then the problem is fixed. I'm 99% sure the problem is fixed, but I'll let you know if it does happen to come on after a little more driving.

[celicaboston1983]

thanks keep me updated. I did safety only this yr so no emissions test this yr.

[6strngs]

bad news. CEL came back on again! I'm stumped. I have no idea what it could be.

[freakyre33c]

most of the time its your o2 sensor

[6strngs]

most of the time its your o2 sensor

how would the o2 sensor throw a code for the EGR?

[56willysnut]

Did you check to see if your EGR Vacuum Switching Valve is working properly?- it's attached by a vacuum line to the EGR valve and is a soleniod for controlling the opening and closing of the EGR valve.

< from alldatapro.com tech manual>
Unbolt it and use a volt meter to check that there IS continuity between the terminals. Resistance should be 37-44 ohms at 68deg F. If there is NO continuity replace VSV. Check for continuity between each wiring terminal and the valve body, replace VSV if continuity IS found. Inspect VSV operation blow air thru the hose that was removed from the EGR valve, air should blow from the filter. Apply battery voltage 12Volts across valve terminals then blow thru hose air should not blow from the filter. If not as specified replace VSV.

See if that helps you troubleshoot the problem. Let us know.

[56willysnut]

Check these areas too;

Code 71 EGR system malfunction only. Deteching condition; Gas temp is 158deg or below for 50 seconds under the following conditions.
Coolant temp 140deg or more
EGR operation possible, ie auto trans in 3rd or manual in 5th @55-60 mph flat road.

Check for items below per alldatapro.

1. A short or open in the EGR gas temperature sensor circuit-
2. Short in EGR vacuum switching valve circuit
3. Clogged gas passage
4. ENgine Control Module problem

[6strngs]

I replaced the vacuum switching valve at the same time as the EGR.

for a little while the light would come on for a while, then go away, now it just stays on constantly. I might try to inspect for more possibile things gone wrong tomorrow or this weekend. I need it smogged before next month!

[6strngs]

ok. wow. I'm stupid. So, I thought the vacuum module and VSV were the same thing. so, I replaced the vacuum module, but not the VSV. BUT, at one point in time, only shortly before my CEL came on, I had unplugged the two hoses from my VSV for a while (I was trying to disable my EGR some more power... when I reconnected it was when I had problems) so, some thought occured to me today, what if I mixed those two little vacuum hoses up and plugged them in wrong? so, I switched them, and reset my ecu. I did what the BGB said to do after resetting the ECU to clear a CEL. which was to jump the TE2 and E1 terminals in the diagnostics box, start the car, turn off all accessories, and let it warm up all the way and then idle for 5 minutes. well, the car was already warmed uo, but I let it idle for about 7-8 minutes. and the CEL never came back on. so, I can't say for sure until I drive the car around for a day or two. but I may have fixed it (though, I've said that before and been wrong). So, it may be that the VSV has gone bad for you and all the other people on here that are getting the code 71. or they just mixed up the hoses like I did. i don't know for sure yet though.

[6strngs]

didn't work. nevermind. I have no idea. I think I'm going to go buy that resistor to put into the sensor so that the engine thinks everything is ok. at least so I can get smogged to buy time until I can figure out what is really wrong.

[alltracman78]

Have any of you bothered to see if the EGR passage in the head/intake man is blocked?

*Or the pipe, if it isn't part of the valve. I can't remember which 5SFEs have which...*

This post has been edited by alltracman78: Mar 17, 2007 - 4:15 PM

[6strngs]

Have any of you bothered to see if the EGR passage in the head/intake man is blocked?

*Or the pipe, if it isn't part of the valve. I can't remember which 5SFEs have which...*

I'm not sure what you mean. on the 5s, the EGR valve is bolted straight onto the intake manifold and has a pipe that comes from the bottom of it. and yes, I did try to clean the pipe passage-way with engine degreaser. then rinsed with water in a sink.

btw, I should really try to learn what the parts are before I call them something. so, basically the two hoses I swapped last night were on the BVSV for EVAP. but yet, the vacuum hoses from EGR and EGR vacuum manifold connect to it? and, I don't know where the two hoses from the actual VSV lead to... so, tomorrow hopefully I'm going to rip out the entire EGR system and check all the vacuum hoses, and clean out any passages I can. I might also seafoam the engine and see if that also clears carbon out of any EGR passages. I'll report back with my findings.

This post has been edited by 6strngs: Mar 18, 2007 - 12:49 AM

[alltracman78]

Some 5SFEs have the valve and metal line as one piece IIRC.
Others [such as apparently yours] have the metal line separate.
If you already cleaned yours out, that pretty much rules it out.

There is a passage in the head from the #4 exhaust port[s] [educated guess, I've never actually probed to see where it goes] to the fitting that metal hose threads to. If this is clogged it will cause that code.

Also, the hole in the intake manifold where the EGR valve bolts to can get clogged. It's not as likely, but if it does, it can slow/stop flow.

I am a big proponent of Seafoam. I've used it many times on my cars.
The only thing I stay away from is using it in the oil.
Anyways, unfortunately it won't do much for the EGR. Not unless you directly soak the passages with it. They make another product called Deep Creep that is basically a spray version of it [think PB Blaster]. You can try sourcing this and soaking the area. But a screwdriver [be careful with it] and a rifle brush is probably best for this.


Your 2 EVAP vacuum lines have nothing to do with EGR. They happen to be grouped with the EGR vacuum lines [think of it as a vacuum line harness instead of a wiring harness].
One goes from the canister to the BVSV, the other goes from the BVSV to the TB. This one has a check valve in it I believe. Very small brown plastic piece in the line.
All of your vacuum lines are marked [as long as they are OEM], so you can tell which is which. Look at the length of them. They will have a number and/or symbol next to it. Like #4 or *3. The other end of the line has the same symbol.

If the EGR vacuum lines aren't routed correctly [which I think you already pointed out] you can get a code.

Also, one more thing.
5SFEs tend to leak oil from the rear of the valve cover and HG.
This oil can get on electrical connectors and distort/block signals.
So if your EGR VSV and connector are covered in oil, this could also be causing the problem. I assume you know where they are.
Don't clean them with brake cleaner. It dries plastic. Use a plastic cleaner, or a quick disconnect cleaner. It will tell you on the bottle if it's safe for plastics or not.

and EGR vacuum manifold

It's actually a vacuum modulator. AKA the EGR modulator.
If you still have the emissions sticker under your hood [on the underside] it has vacuum hose routing info.

[6strngs]

Some 5SFEs have the valve and metal line as one piece IIRC.
Others [such as apparently yours] have the metal line separate.
If you already cleaned yours out, that pretty much rules it out.

There is a passage in the head from the #4 exhaust port[s] [educated guess, I've never actually probed to see where it goes] to the fitting that metal hose threads to. If this is clogged it will cause that code.

Also, the hole in the intake manifold where the EGR valve bolts to can get clogged. It's not as likely, but if it does, it can slow/stop flow.

I am a big proponent of Seafoam. I've used it many times on my cars.
The only thing I stay away from is using it in the oil.
Anyways, unfortunately it won't do much for the EGR. Not unless you directly soak the passages with it. They make another product called Deep Creep that is basically a spray version of it [think PB Blaster]. You can try sourcing this and soaking the area. But a screwdriver [be careful with it] and a rifle brush is probably best for this.


Your 2 EVAP vacuum lines have nothing to do with EGR. They happen to be grouped with the EGR vacuum lines [think of it as a vacuum line harness instead of a wiring harness].
One goes from the canister to the BVSV, the other goes from the BVSV to the TB. This one has a check valve in it I believe. Very small brown plastic piece in the line.
All of your vacuum lines are marked [as long as they are OEM], so you can tell which is which. Look at the length of them. They will have a number and/or symbol next to it. Like #4 or *3. The other end of the line has the same symbol.

If the EGR vacuum lines aren't routed correctly [which I think you already pointed out] you can get a code.

Also, one more thing.
5SFEs tend to leak oil from the rear of the valve cover and HG.
This oil can get on electrical connectors and distort/block signals.
So if your EGR VSV and connector are covered in oil, this could also be causing the problem. I assume you know where they are.
Don't clean them with brake cleaner. It dries plastic. Use a plastic cleaner, or a quick disconnect cleaner. It will tell you on the bottle if it's safe for plastics or not.

and EGR vacuum manifold

It's actually a vacuum modulator. AKA the EGR modulator.
If you still have the emissions sticker under your hood [on the underside] it has vacuum hose routing info.

thanks for the info. I never checked the hoses for markings or anything, but I don't think they have any.

I found a diagram in my hayne's manual that shows all the vacuum lines for 92 and up 5sfe's, and the way it looks, the hoses from the EGR and vacuum module route to the BVSV for the EVAP. but, it could be just confusing in the diagram, cause it's not easy to see. I will find out where they really go today because I'm going to pull the entire EGR system off, inspect all passage-ways, check and replace as necessary all the vaccum lines, and possibly replace the VSV. if that still doesn't work, I bought a 4.7K ohm resistor yesterday so I could make the CEL go away the cheating way. lol

[alltracman78]

Haynes is only good for so much.
Check for that sticker.
It will tell you what hoses go where.

EGR and EVAP do NOT share hoses.
If Haynes is telling you otherwise then they are wrong.

IIRC one of the 3 on top of the TB goes to the BVSV. It's not part of the EGR system, but because of location you might be confusing it as such....

[6strngs]

yeah, you're right. EVAP and EGR don't share hoses. lol. it kinda confused me because there's a bunch of hoses that all run into one big hose and then that big hose splits into smaller sections and stuff. hard to explain. anyway, I pulled the entire EGR system off, except the VSV, which I couldn't find. I was using the underhood label to follow hoses to find it, but the way it looks, it's so deep in the engine bay I might need to removed the intake manifold to get to it. anyway, so after pulling it all off, not finding anything wrong, and I cleaned the port from the exhaust that goes to the EGR valve using Q-tips. I put it all back together, reset the ECU again, and started driving. well, I was out and about, drove for about 75 miles, stopped and started the car 3-4 times, and drove for over an hour and a half and the CEL never came back on (usually it comes on way before driving that much) I'm not gonna get my hopes up, but I'm saying it may finally be fixed, even though I didn't really do anything really.

[6strngs]

so, another day of driving and the CEL still has not come back on! woot! perhaps all I needed to do was clean that port from the exhaust, even though I really didn't clean it all that thoroughly, I just took a couple Q-tips and shoved them in there, they went it white and came out black, so I must've cleaned something. either that, or the seafoam I used helped clear something out. I only used seafoam in the intake, not the oil or the fuel.