94 GT 5.0 performance problem help

[bflynn]

My 94 GT 5.0 statring having a problem. In low gears it is the most noticeable. It feels like I am pulling and lead anchor, it just won't go. I am getting about 50 miles per tank less on fuel milage. Top end seems to still be there. If I kick it into passing gear, it just ups the rpm's and does not acclerate. I have had it tuned up, replaced the catalytic converters, the oxygens sensors. It is better but I can still be beat at low end by hondas. Just prior to replacing the 2 O2 sensors, I was receiving the following codes. Any ideas what my problem is?

172 Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control
176 Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control
181 Fuel system was lean at part throttle Single, Right or Rear HO2S - Fuel control
189 Fuel system was lean at part throttle - Left or Front HO2S - Fuel control

 

[bill302]

sounds like your tranny is slipping in low gears.

 

[VibrantRedGT]

If you have an adjustable fuel regulator you need to up the fuel pressure a few psi. Clear the codes and go run it hard. If your still getting lean codes then keep turning it up. I had the same issue some time ago. I use to have a nasty lean pop at high rpm's. If you don't have one your car is telling you to get one.

 

[bill302]

oh ya welcome to :SNSign:

 

[DoctorB712]

I'm not 100% sure but I had lean codes last summer. Someone told me to clean the MAF sensor with air intake cleaner. Did it and gone. For 5$ and 15 minutes it was worth it. I dont remember the exact code but it sounded like yours!

Hope it helps

 

[CManT1914]

I think we really need some information on what he has done to his engine. Is it stock?

 

[droptopford 5 0]

I'm not 100% sure but I had lean codes last summer. Someone told me to clean the MAF sensor with air intake cleaner. Did it and gone. For 5$ and 15 minutes it was worth it. I dont remember the exact code but it sounded like yours!

Hope it helps

its probably more in depth than this, but my low end gave out on me, my mpg went down and i was throwing the 189 code when my MAF was dirty, just spray some electronic contact cleaner on the little wires inside the MAF, its worth doing wither way if you havnt done that yet, even if you dont think this is the problem. oh ya, i was also getting a part throttle ping as time went on with this problem. good luck wither way