Hello everyone, I have a 2001 S2000 with a f22 swap from a 2005 in it. It has a matching ap2 ecu. I have a P0171 lean code and a high fuel trim in the 28-30%. I have replaced the map sensor, fuel pump, FPR, sent the injectors to be cleaned and flow tested with no luck. The car also has a slight misfire with no CEL. I couldn’t find any vacuum leak when I smoked the car. Any help is appreciated.

 

Have you checked valve lash?

 

What is the STFT at idle? Can you post the freeze data?

Is the intake manifold gasket brand new oem?

 

All parameters show what the ecu is SEEING. Temp, map, state of sensors, etc.

Fuel trim shows what the ecu is DOING as a corrective action. In this case, the ecu is adding more fuel, to make up for a lack of fuel, or compensate for TOO MUCH air (typical of an ap2 swap) the 2.2L is simply pumping more air, via basic displacement mechanics.

What parts of this swap are left over from the AP1?

 

at idle the STFT was in the high 20s and no the intake manifold gasket is the same one as I didn’t remove the intake.

 

The only parts I reused from the ap1 were one cam position sensor (old one was cracked), idle air control valve, harness, fuel feed line, and both oxygen sensors.

 

yes I did a valve adjustment twice and found one valve overly tight. Fixed that with minimal improvements. The engine was claimed to be sub 30k miles and has 220-220-210-220 from the compression test. Leak down was also good along with mechanical timing.

 

You may need an ap2 primary oxygen sensor. The sensors have different calibrations.

 

Ok thanks, I ordered a used ap2 one in good condition to see if that helped. My O2 readings were normal at idle with fluctuation between 0-.9v on the old oem sensor. I’ll let you know if anything changes.

 

Reference point: my 05 f22 in my Ap1 ran well on both 00 and 05 ecus.

Can you verify fuel pressure? Sounds like a lot of unmetered air. Can you put in the 01 ecu and see what happens?