Hey guys, I have a 1994 Camaro. I recently acquired the car, and the car was built as it is when I got it for the most part. The engine is a 383, has AFR 210 heads, 565 lift nitrous cam, lt4 intake, hooker long tubes, etc. The issue it is having is once it warms up and goes to closed loop, it starts running terribly. I have put 3 sets of O2 sensors in, New mass air, New temp sending unit. Has an MSD optispark that's less than 2 months old, New plugs, wires, New racetronix fuel pump and hotwire kit. Still having the issue. I have my right bank reading much leaner than the left also. Just wanting to see if anyone may have any ideas if where I should head from here?

​​​​​​​thanks in advance!

 

Have u checked for vacuum leaks?

 

Yes I have. I have checked for vacuum and exhaust leaks and have nothing. I had a new ICM and coil I am installing now but I don't forsee that fixing the issue unfortunately.

 

What brand o2's have you been using? Stay away from Bosch. Also, once it warms up, will it restart immediately if you kill it? If not, try holding the gas pedal to the floor while cranking. If it starts, it's a sign of bad coolant temp sensor in the water pump, or bad wiring to it. I've dealt with both of those issues.

 

Check for burned/melted wires going to the O2 sensors. I had wires get up against the headers on the passenger side and the car acted much like you are describing. I couldn't find the problem and even the shop had a very difficult time finding what was wrong. The wiring was melted together, so testing still showed continuity, but evidently signals were all messed up when the PCM was trying to read the sensors.

 

I pulled the entire harness up and there are no burned/melted wires. All connections were good. Extended O2s and BLMs went to 128 for a few minutes while running, then went back to 160. O2s read from 40 up to 800 MVs while driving, at idle it's at 30-60 MVs. WOT runs fine. To give all information, Engine specs are as follows:
383 CI, afr heads, 11:1 compression, LT4 intake, 565 lift cam(rest of specs unknown as motor was in car when I got it) MSD opti, Hooker super comp long tubes. I cannot figure out what's going on and its driving me crazy. Any other suggestions?

 

Follow-up on some of tips listed here - coolant sensor, 02 sensor (brand); was the vehicle tuned at all following the modifications?

 

+1 on the tune. My last LT1 was doing this and had a few of the issues mentioned here but the main issue was the tune turned out to be totally crap.

 

I have been leaning towards the tune. The guy who built the car had it tuned by PCMForless, so it's never been tuned in person. That will probably be the next step.

 

The only DTC that is showing up is code 64 for right bank lean. Again, this shows once it goes into closed loop. Any other suggestions before it goes to the tuners?