UPDATE: Been a long time, but I am still having this problem.
I installed a new O2 sensor, OEM Bosch unit, and still get code 1222. The engine starts fine, idles fine when cold, but sometimes wavers between 600 and 900 rpm, only when warm. Typically only does this when I do a hot restart. Another note, sometimes this thing has a very hard time restarting when hot and I have to floor the gas and crank for 5+ seconds. Giving it gas off idle, it stutters a bit, and isn't too quick to respond, but never stalls.
Still have the same symptom of CEL always on. If you pull the ECM harness to reset it, then drive again, it comes back on initially only at idle, and goes away when you give it gas, but eventually comes back on at cruising speed and stays on. Only fault code is 1222.
Have checked for vac leaks, found a tear in the intake boot, replaced it, same problems. Checked again for vac leaks by blowing smoke into the intake and found none.
Tested resistance on coil, was a bit high, put a known good one in, same issues.
Got a good ICV for free, swapped it, same issues.
Got a good AFM for free, swapped it, same issues.
Tested plug wire resistance and it was within spec.
Spark plugs are NGK coppers and have about 1000 miles on them.
When it got warmer out, I smelled gas and it turned out the gas cap leaked vapor. I replaced it, no more leak, and same issues.
Swapped ECMs, no difference.
Valves were adjusted 4k miles ago.
I wire brushed all the grounds I could find.
I'm honestly at a loss for what this could be, especially because the symptoms are that of a typical vacuum leak. Is there any non-obvious spot where there could be a vacuum leak, like the EVAP system or the brake booster? Should I pull the injectors and have them tested? I tested the resistance and they all checked out, but could they be leaking or firing intermittently?
I installed a new O2 sensor, OEM Bosch unit, and still get code 1222. The engine starts fine, idles fine when cold, but sometimes wavers between 600 and 900 rpm, only when warm. Typically only does this when I do a hot restart. Another note, sometimes this thing has a very hard time restarting when hot and I have to floor the gas and crank for 5+ seconds. Giving it gas off idle, it stutters a bit, and isn't too quick to respond, but never stalls.
Still have the same symptom of CEL always on. If you pull the ECM harness to reset it, then drive again, it comes back on initially only at idle, and goes away when you give it gas, but eventually comes back on at cruising speed and stays on. Only fault code is 1222.
Have checked for vac leaks, found a tear in the intake boot, replaced it, same problems. Checked again for vac leaks by blowing smoke into the intake and found none.
Tested resistance on coil, was a bit high, put a known good one in, same issues.
Got a good ICV for free, swapped it, same issues.
Got a good AFM for free, swapped it, same issues.
Tested plug wire resistance and it was within spec.
Spark plugs are NGK coppers and have about 1000 miles on them.
When it got warmer out, I smelled gas and it turned out the gas cap leaked vapor. I replaced it, no more leak, and same issues.
Swapped ECMs, no difference.
Valves were adjusted 4k miles ago.
I wire brushed all the grounds I could find.
I'm honestly at a loss for what this could be, especially because the symptoms are that of a typical vacuum leak. Is there any non-obvious spot where there could be a vacuum leak, like the EVAP system or the brake booster? Should I pull the injectors and have them tested? I tested the resistance and they all checked out, but could they be leaking or firing intermittently?
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