kkkk

Could a leaking injector cause a low RPM single cylinder misfire @ 1500RPM only?
Do injectors work by % throttle, or are they controlled via engine RPM?
I also have negative fuel trims. (Rich)

deadlyvt

Injectors work on airflow from the meters (throttle is what allows more or less air from flowing) and rpm
More than likely you have a spark plug or coil issue easy to try switching coils see if a different cylinder begins misfiring or pull the plug and have a look
how many miles on your car?

hachiroku

have you scanned your ecu for faults? i'd be odd if your car was running rich on both banks of cylinders. when was the last time you replaced your oxygen sensors?

kkkk

hachiroku

if you've replaced oxygen sensors and not cleared computer of all codes, misfires prior to install will continue to exist. the ECU will need to relearn.

kkkk

Yeah, ecu codes have been cleared after replacing the O2s

Dogtag114

Funny, I have had the same issue the last two months... I tried reloading the stock tune and also installing Eurocharged v7 over v6... all did it.

I had the car serviced for another reason and asked to diagnose this too... they found nothing, no codes, but also felt it... they said sometimes this happens as a precursor to the intake manifold failing and to watch a few months to see if it throws out that code (which it did maybe 4 months ago and I erased it, then had my head bolts replaced in June).

I'll live with it until it is a bigger problem since I just dumped about $5k of repairs in at 99k miles... she just doesn't want to get to 100k cheaply...