: Just wanted to check on some codes P0171 and P0134



codewize
05-17-08, 09:58 PM
So, it started with the P0171 - Fuel Trim System Lean Bank 1 so I assumed that I had a leak in the intake somewhere. I have not investigated that yet.

The I began seeing P0134 - Heated Oxygen Sensor (HO2S) Circuit Insufficient Activity Bank 1 Sensor 1. Which I'm being told would NOT be set by something esle causing bad readings and that this code is hardware related.

So now I ask, am I dealing with 2 separate issues? Or are the 2 codes related? Just wondering where to start.

Ranger
05-17-08, 10:34 PM
I'd start with the vacuum leak. I think it could cause the other DTC.

Submariner409
05-17-08, 10:36 PM
Which car ? Given the code string I'd guess the 2001. Clear the codes. If 0171 comes back, intake or plenum leak. 0134 would be a "lazy" O2 sensor, because that is set "downstream" of the engine proper (in an exhaust manifold sensor). If it's the 2001, how many miles ?

codewize
05-17-08, 11:56 PM
Oops, yes the 2001 with 61k

codewize
05-18-08, 11:45 AM
Hmmm Maybe this should have gone in the Deville forum.

AJxtcman
05-19-08, 07:38 AM
I will take a look at the PCM's you had and look at the order you ran them. I will look to see if I have an O2 sensor to mail you also. I guess one of the program may have been too rich and contaminated an O2 sensor. The O2 heater code and the lean code are not setting together. One may set on one trip and the other will set on another trip. Both can be set by a bad O2 sensor.

codewize
05-19-08, 09:17 AM
Hmm you think that could be it? The lean code started setting with the PCM that I liked.

Then I stopped looking at the codes and just kept clearing them but I think you're correct in saying that they don't get set together.

So then I decided to look again and that when I discovered that there were in fact 2 codes involved. Hmmm interesting



I will take a look at the PCM's you had and look at the order you ran them. I will look to see if I have an O2 sensor to mail you also. I guess one of the program may have been too rich and contaminated an O2 sensor. The O2 heater code and the lean code are not setting together. One may set on one trip and the other will set on another trip. Both can be set by a bad O2 sensor.