Lambda Emissions Control CEL

[robcarync]

Greeeetings!

I have a 95 318ti active.

I keep getting an intermittent check engine light. I have the peak scanner tool and the chart says it is the emissions lambda control. I searched through here but didn't find much information and couldn't find much in the Bentley Manual...anyone have any insight as to what this could be? I read on here that the o2 sensor is a lambda sensor...but there is a seperate fault code for the o2 sensor so I am not sure what this means.

On a side note, the CEL only comes on when my foot is off the gas pedal. If I idle for a little bit, it will come on. If I am driving and take my foot off the pedal, it comes on. The instant I tap the gas pedal at all the light goes off.

I also have a code for knock cylinders 3/4 which I had replaced that sensor about 2 years ago so I would hope it is not bad again! Maybe the 2 codes are related?

-Rob

Thanks!

[668M42]

regulating lambda probe lol. that what our system here at bmw refers to the o2 sensors as. so if you can afford to, I'd guess that you should give the o2 sensors a try. if you get me that p code that your peak scanner gave you, i'll try to generate the code that bmw would use (since techs don't use p codes here at the dealer) hopefully that helps friend!! lemme know :-)

[robcarync]

peak scanner tool gives me a c9 for the lambda emissions control and a 2a for the knock cylinder I believe.

I will double check the code chart when I get home where my book is....

[robcarync]

confirmed....c9 was the peak code for emissions (lambda) control

2a was for knock sensor cyl 3 and 4...though i cleared the codes and the knock sensor went away but c9 continues to show up!

[668M42]

Originally Posted by robcarync

confirmed....c9 was the peak code for emissions (lambda) control

2a was for knock sensor cyl 3 and 4...though i cleared the codes and the knock sensor went away but c9 continues to show up!

ok... when i go to work today, i'll see if i can generate a bmw code for you and possibly a better description of what your issue is and what you need

[robcarync]

Bump...any info?

[bmwconnect]

I would suspect a clogged or failing fuel injector

[robcarync]

Problem solved: upon further research, a bad crankcase ventilation valve can cause: rough idle, intermittent check engine lights, and high pitched screeching sounds...all which I had.

$70 part, 2 bolts, and a pain in the tail to get to the two bolts out/back in, but the CEL is off permanently the idle is smooth.

At first my car died a few times and I thought I made it worse by replacing the hose and valve...then I realized I was an idiot and forgot to plug back in the MAF which I had removed earlier for something else.

It sure feels good to have a smooth ride now!