99gt302

I have a 2007 mustang gt.

JLT 110mm Cold Air Intake
Long Tubes
SCT X-Cal
Hot Rod Cams
o/r x-pipe (no cats)

Car has had mods for quite sometime and had no issues. Last week I got a 02 heater failure code and went ahead and put two new upstream 02 sensors in. Check engine went off for about 3 days. I fired it up and drove it the 3rd day and got another check engine light. This time it was a p2197 (b2, s1 stuck lean) the car is missing & sputtering. Again the 02 sensors are new, and the car has ran fine for months before all of this, no new modifications that would have caused this.

One thing we noticed when checking it on the scan tool is that the drivers side o2 was running slow compared to the passenger side.

I checked for loose intake clamps and pcv and everything seems fine. Any suggestions on what to check for? Thanks!

moosestang

Are they bosch o2 sensors? If so, I'd recommend replacing them again with the motorcraft sensors. You can get them through rockauto for $40 each.

Google bosch o2 sensor slow mustang. That will get you a bunch of posts about bosch sensors on our cars. Here's Justin Starkey's rant about them. http://vmptuning.com/forum/showthread.php?t=825

Replacing those upstream 02's is fun, ain't it. The drivers side 02 is a biotch to remove and install.

S197GT07

Awesome info on the O2's. I used the rockauto's OE replacements and my car runs great btw.

Also, my ARH make front O2 swaps take about 5 min

99gt302

It was still slow with factory o2's in it as well... easy to change with the long tubes.

99gt302

Would that slower o2 cause the p2197? i checked for vacuum leaks yesterday spraying starter fluid all around with no luck...

moosestang

I bet it does. I'm not going through the hassle of installing long tubes just to make o2 sensor replacement easier.

moosestang

Well your factory 02's could be slow because they are worn out. the Bosch 02 sensors are slow because they are slow.

99gt302

Well, I just ruled out vacuum leaks, did a smoke test. No leaks.... next step is checking for exhaust leaks....any other suggestions?

Ordered some of those sensors from rock auto.

moosestang

Don't feel too bad, I have some almost new bosch sensors in my tool box. I noticed mine were slow while data logging, but hadn't gotten a code yet. After googling it, i came across the posts about them being slow.

99gt302

bump...still having the issue... It seems to be running pretty damn good except when it is cold and I first start driving, it jerks a lot.