P0171:problem.

atrixblue.-MFR-.

mate pulled up tonight the EML came on as the garage was shut i took out my Fault code reader, and done the read P0171=system too lean bank 1. so asked him to run it till it warmed up fully. 15 mins later i looked at freezeframe and the oxy sensor is showing INC (incompleted operation) as are a few others exhaust related.

done a few cars with p0171 and usually its been the maf/airtemp sensor, a good clean with carbcleaner problem sorted, but the freezeframe has always shown the oxy and others to show ok.

so naturally this has thrown me a bit as maf and exhaust oxy sensor are fuel related in the sense of fuel delivery.

clear the code the symptoms go:

rich smell of exhaust fumes.

slight smoking.

engine performance drop (limp mode)

card drives fine after code gone but will re appear once at idle temp.

im leaning on the side of lamda sensor has gone as freeze frame has show INC BUT that could be that limp mode is activated before the sensor has had a chance to read anything.

what do you guys think.

Rossy.

Sounds like the Lambda sensor is fubared

What car is it?

atrixblue.-MFR-.

Rossy. wrote: »

Sounds like the Lambda sensor is fubared

What car is it?

it a mates chrysler neon he hasnt had it long and just called him actually to read through his warrenty terms and cons, sensors and other certain electrical isnt covered.

i might pull the plug on it for him, at least the fuel ratio will return to the norm.then on a better day ill pull it out and clean it carefully as with maf sensor.

could be both thats flown the cukoo's nest to sensor heaven.

Rossy.

atrixblue.-MFR-. wrote: »

it a mates chrysler neon he hasnt had it long and just called him actually to read through his warrenty terms and cons, sensors and other certain electrical isnt covered.

i might pull the plug on it for him, at least the fuel ratio will return to the norm.then on a better day ill pull it out and clean it carefully as with maf sensor.

could be both thats flown the cukoo's nest to sensor heaven.

I defo think it's the Lambda sensor

They cause all sorts of issues when nackered

Overfuelling, limp mode etc

atrixblue.-MFR-.

Rossy. wrote: »

I defo think it's the Lambda sensor

They cause all sorts of issues when nackered

Overfuelling, limp mode etc

yeh i had this issue with a pug 307, it was the common problem of the manifold cracking in two parts causing the oxy sensor to deliver more fuel due to excess air in the manifold you really couldnt see the crack with the heat sheil off untill you looked at the underside of the heatsheild to see black soot lines,some crack bad as to see into the manifold and some hairline crack and untill you indo it and get to bolt on cyl 3 and then the manifold drop off leaving the other half on it you get to see how bad it is.

but my mind flew to lambda as soon as freezeframe brought up those results, other than that its a really nice tidy car, they dont suffer with the head gasket failure as its a neon mk2 and the problem was sorted in mk1's in 1998.