FivePointOhh

ok, i ran codes and this is what i got. the problems i'm having is poor running conditions during cold start up, first one of the day. but i did run the koer codes at about 120*....not sure if that matters.

koeo:
34-85-29

koer:
29-41-91-34

Joel5.0

29 is a problem with the Vehicle Speed Sensor (VSS), make sure the sensor at the transmission is not unplugged.

34 is EGR Valve Position Voltage Above Closed Limit (O,R), EVP circuit has intermittently failed above the closed limit of 0.67 volts (M) .....make sure the EGR valve is seating 100% (sealed) and not causing a vacuum leak that will affect idle...... if the EGR valve is OK..... the EVP sensor is most likely kaput.

41 & 91 = System lean codes..... you should check fuel pressure, vacuum leaks, and make sure the HEGO ground at the back of the intake is bolted to the intake or cylinder head (Orange wire tagged with #19 in the harness diagram below).

Foxbodyforever

if you have any exhaust leaks around the o2 sensors in your exhaust you might get a 41 code from the extra oxygern coming in through the holes

FivePointOhh

checked the sensors around the transmission and everything is plugged in. and now the codes doesnt show up anymore. maybe something was just loose.



the egr is new and seating 100% i have put high tack gasket sealer just to make sure. so im guessing its the evp like you said, cause im still getting the codes. btw...whats EVP and where is it located?

for the system lean codes(obviously not lean cause the smell of gas just hurts my eyes.) FP is set at 35w/o vac, no vac leaks that i can find(carb cleaned the hell out of every vac line.). the HEGO ground i cleaned all surfaces all down to bare metal. so the ground is good on the back of the driver side cylinder head.

any other ideas how to fix 41 and 91 codes?


also i ran the cylinder balance test and it actually bleeped cylinder 7 is weak. is that test even supposed to work on our cars? my book says it doesnt always work for 87 and newer.

Joel5.0

EVP is the EGR Valve Position sensor .......

For the lean codes, you may have to check the O2 sensors...... follow the test diagram below and LUK.