6G Celicas Forums

UPDATE: So I jumped the gray sensor and so far no code. Drove it for long enough to throw it.

Also traced the flickering oil light. It only flickers over bumps. The ghetto wire splice is almost surely the culprit, so I'll get the soldering iron and shrink tubing out and hit it tomorrow or Sunday. Bought some RTV to slap on the block where the seam is above the alternator mount. That should end that little oil leak.

So then the car will be code free and running well instead of code-red and running well. :lol: I'l let you guys know how it goes.

Thank you again for sharing your knowledge with me.

I may take you up on that.

The gray plug shown in this picture, tied to the firewall?



I'll try that this weekend, and I'll update here with results. It threw the code during a short drive last night, which I cleared. It did NOT come on this morning on my way to work, which is a longer drive. Still no sign of the knock code. I'm more convinced now that it was simply old gas, as the tank was nearly empty when I bought it and the car had been sitting.

Thank you very much for the help. If any of you ever gets a last gen Impreza (GD chassis), I hope to be able to pay you back in kind.

Post'em anyway as I'd like to know where to look for the EGR in case I want to replace it.

UPDATE:

So the knock code has not returned. Just the EGR code. As I cannot find the EGR on the car, I can only guess that whatever existing bypass was there has failed. I have to find it. Any suggestions?

Also, I'm getting 29.8mpg in mixed driving. Does that sound right to you guys?

Also, bump for whether this picture of the cluster (engine off, key to ON) means anything else needs replacing:

Ah, so the airbox itself is not the correct size/shape, or the hosework on the opposite side isn't. Like someone else said, probably not the correct airbox to the car, but it seems to get the job done.

Thanks for the information on the knock sensor.

So here's where I'm at:

I need to know how to "bypass" that EGR circuit so the code doesn't trip anymore, since it's obviously not that big of a deal.
I need to know the specs on uninstalling/installing a knock sensor - which I know I can find at toyotapartsbarn for a halfway decent price.

Is there anything else you guys think I should consider? And can anyone walk me through a bypass (what/where exactly to perform the bypass more than how )? I'm going to throw some fuel injector cleaner in the tank on the way home and top off with some 93 octane for a bit of insurance (and to calculate mileage to see if the gauge is lying to me).

This is what my cluster looks like when the car is off but the ignition is turned to "on":



Everything but the CEL goes off when it's running. I checked the oil several times. It's clean (fresh change) and full.




Sorry: 52 and 71 are the codes. My mistake.

Thanks everyone for the responses so far. God I love the internet sometimes.

I was bored with the STi, honestly. Looking for something a bit more grown up. Not sure what, yet, so the Celica beater it is. For now.



Okay. So, if the EGR is malfunctioning, that's not really all that bad. I understand what a knock sensor is, I was more wondering why it would be unplugged. :lol: Any idea where that sensor is located? There are three knock sensor codes the ECU can throw. Mine threw 51 if that helps at all. I'll replace it ASAP once I know where it is.

Ah. That makes me feel a bit better. I think. :lol: TIA for the pics. Like I said, it runs very well and drives normally. Just throws codes.

What are the consequences of bypassing that thermostat? I will be (eventually) driving the car over distances in excess of 100 miles and don't wish to be stranded.

Also, why would the knock sensor be unplugged? In an OBD1 car, does the sensor throw a code if it detects knock or only if it is not functioning?

These codes are not thrown immediately at startup and instead require driving around for some random distance. Would they really take that long if the thermostat wasn't functioning or the sensor was unplugged? Forgive me. I have basic car knowledge, but I'm going to ask often for clarification. I appreciate your response very much.


Thank you! And hooray for the bugeye wagon. Just sold my 06 STi - or am about to rather.

PHOTOS:

From the driver's side looking down at the headers, which are obviously not stock - not that sensor hanging out down there.


And a bit closer up:


Back on the firewall, it looks like this. Note the sensor connector zip-tied up. There are actually three sensor plugs in that harness that are not plugged in:


Another angle of that area. The sensor plugs are a little out of frame toward the top:


Toward the firewall on the passenger's side:


Airbox - not that the battery is apparently backwards, so the ground is stretched taut. Looks like it should be slack. Also looks like there's some sort of hose elbow missing between the airbox and some duct that comes from beneath the fusebox:


Lastly, under the alternator and towards the passenger's side of the motor, there is (by the oil filter) a sensor. Is that a knock sensor? If so, there's a tiny strip of yellow wire that looks like it's on its last legs connecting it to something I cannot yet see. Could this be why I'm getting the knock code or have I misidentified that sensor? This is the area - if you had X-Ray vision, you'd see the wire I was referring to. :lol:


Any help is appreciated, guys. I know Imprezas, not Celicas. Tell me what's wrong with these pictures so I can go about getting it corrected.

So I'm getting code 51 (Knock Sensor) and 72 (EGR system) codes on my 1994 ST auto. I just got the car extra cheap as a beater and frankly know little about it. I know it is not stock.

The car runs (but is slow to me, but that's the nature of it I think). The engine runs and idles smoothly. The AC works, etc. These codes come on at random while driving and stay on until cleared (this has happened twice in my 100 miles of owning it). Gas mileage seems to be superb. The engine temp gauge on the dash barely goes above 1/4 of the way up, and it stays where it is after it reaches that position.

So, 6g gurus, what do you suggest. I will attempt to post some engine bay pics early this afternoon. This will soon be my only car and I need it to run well for at least another 50k miles. It has 190k on it, new belts (including timing), new seals (including rear main), and new gaskets.