2001 acura integra gsr 1.8 vetec

customer complaint poor gas mileage and stinks of raw fuel checked. had extreme false lean code

1 fuel pressure in spec forget what spec is off of my head but it matched what all data had 40?psi at idle
2 map sensor reads 2.8 volts with key on engine off 1.1 running
3 checked for sticking purge valve
4 checked coolant temp sensor its accurate
5. front o2 was dead lean rear o2 full rich (replaced front o2)
6 tps reads .5 volts at idle
7. engine vacuum 17.5-18 inches
8 short term fuel trim 45% long term 20% prior to o2 sensor replacement after (short -25 long -10)

the car stunk up the entire shop prior to o2 sensor removal now it doesnt stink but why so negative trim numbers??
any suggestions im open to. thanks in advance!

How long did you let it run after 02 replacement? Possibly burning excess fuel leftovers. Also maybe check for gas in oil, maybe washed through the piston rings, vapors sucking back in through PCV. Maybe needs a fuel trim reset, and confirm trim numbers go back down to rich. Let me know

ive drove it 10 miles id say. performed an ecm reset with a scanner. didnt unhook battery. i got to thinking maybe the oil has gas in it right after i posted.

Maybe try to force a lean condition by pulling vacuum lines and make sure the new o2 isnt lying.

new o2 works. maybe an injector flow test?? valve adjustment??

I looked up the map voltage. A known good showed .9v at 800ft above sea level. Yours is a little higher which could indicate a valve problem. But you said you had 18inhg, which sounds pretty healthy. Possibly a bad MAP. Substitute a known good map, and check the voltage. Might need to clear memory tables.

I'm with Gjauto, MAP voltage is a bit high. Any accessories on?

I've seen tight valves cause negative fuel trims, but not -35%. Maybe a combination of contaminated oil and valving?

i had the oil changed it improved 11%. when i first seen the car it was at 45% short term and 20% long term due to the dead o2 sensor. might have to find a known good map. but the map sensor passed the bench test voltage vs vacuum right on the dot..

Verify cam timing? Could have been a pre-existing condition?

they said they had another shop do the headgasket on it. im thinking either cam timing or tight valves. everything else is checking out good. but the front o2 sensor was definetly fixed lean.