Badly Seated Fuel Injectors, Would they cause severe shake and hesitation? Options

[Celicatime]

My 94 GT failed the emissions test and so I thought I would be mr. fixit and replace the fuel injectors among other things.
First of all - the injectors are a pain in the axx to get to but when I finally replaced them, I'm not entirely certain I seated them correctly.

I put everything back together and started the car and now the engine shakes and hesitates from the get go and doesn't get any better after warm up. I had a perfectly smooth engine and now it acts like the engine is missing a piston.

Before I go to the work of getting at these stupid injectors again I wanted to see if it sounds likely that my problem is related. (sounds silly to even ask it, but I really don't look forward to doing this job again).

[toyotacrazy]

If you didnt seat them correctly they would be leaking fuel. Maybe you got a bad injector or clogged the injector during installation. It seems first you need to fix the problem that came about after the injector installation. Next, your car barely failed. Could still be a bad o2 sensor. Maybe check the toggle of the sensor through the DLC1. Let me know when you get it running as it was before. brian