1992 w/ 43k miles
relevant mods: headers ’99, injectors bench tested ’02, O2 sensors new with header install ‘99
relevant service: fuel filter, spark plugs ’99 @ 20k miles
symptom
slightly rough idle (missing) and hesitation between 1,500 – 3,500 RPM. No hesitation in this range at WOT. A road test can cause repeatable check engine light #1 (Front Oxygen Sensor Circuit)—closed throttle deceleration in 2nd gear from above 4k to idle.
History
Driving home from an end of season track event last year I noticed a hesitation under slight acceleration around 2-4k RPM. Unfortunately, the hesitation did not go away during the winter, even after refilling with a fresh tank of gas.
Diagnosis thus far
Compression check: ok
Valve clearance: ok
Visual spark plug inspection: ok
Injector coil impedance check: ok
Following the Service Manual flowchart for code 1 (pg. 11-30) then to (pg. 11-36), I cannot produce a 43 code while running engine at 3,000RPM for 2 minutes. I am suspecting a front oxygen sensor or front fuel supply.
Question
Even though front and rear O2 sensors have different part numbers, can I swap them to rule out the O2 sensor as the failure?
TIA,
DanO
relevant mods: headers ’99, injectors bench tested ’02, O2 sensors new with header install ‘99
relevant service: fuel filter, spark plugs ’99 @ 20k miles
symptom
slightly rough idle (missing) and hesitation between 1,500 – 3,500 RPM. No hesitation in this range at WOT. A road test can cause repeatable check engine light #1 (Front Oxygen Sensor Circuit)—closed throttle deceleration in 2nd gear from above 4k to idle.
History
Driving home from an end of season track event last year I noticed a hesitation under slight acceleration around 2-4k RPM. Unfortunately, the hesitation did not go away during the winter, even after refilling with a fresh tank of gas.
Diagnosis thus far
Compression check: ok
Valve clearance: ok
Visual spark plug inspection: ok
Injector coil impedance check: ok
Following the Service Manual flowchart for code 1 (pg. 11-30) then to (pg. 11-36), I cannot produce a 43 code while running engine at 3,000RPM for 2 minutes. I am suspecting a front oxygen sensor or front fuel supply.
Question
Even though front and rear O2 sensors have different part numbers, can I swap them to rule out the O2 sensor as the failure?
TIA,
DanO