my 86 iroc 305 tpi keeps throwing a code 44 lean exhaust code. it has good fuel pressure and i changed the o2 sensor and it still threw the code. i don't have a scan tool so i can't look at any data streams or anything. any input would help thanks

 

A Haynes manual will give you some suggestions. the last time I had a problem with 44 was bad fuel pump. When you say that it has good fuel pressure, I am sure you checked it with a gauge to confirm that. I believe it also may mean you are getting too much air. How about intake leaks?

 

yea, it may be the fuel pump because when i go to start my car up for the first time in the day the fuel pump makes weird noises and doesn't really work. it's actually hard to start now that i think of it. thanks

 

Check all plastic vacuum lines for connection and that they aren't cracked.

Check O2 sensor wire to make sure it's not melted to the exhaust.

Fuel Filter.

Make sure intake manifold bolts are tightened to torque specs. Especially the middle 4.

Check connections after the MAF for air leaks. MAF to Air box to Bellows to TB.

Make sure plastic air box is not cracked. They are bad about cracking right on the seam which is hard to detect.

Long shots:

Plugged Cat or Muffler
Air Diverter Valve malfunction.
Cold start valve leaking air (o-rings)
Injectors leaking air (o-rings)
Bad ECM (unlikely)
Bad PROM (unlikely)

 

MAP sensor?

 

if any injector o-rings are leaking woukldn't there be fuel spiting out or even dripping?