O2 Sensor issues can anyone please Help?
O2 Sensor issues can anyone please Help? My car is a 2002 Z28 A4. I installed headers on it about a week ago. I have the rear O2's turned off. My car is throwing a low O2 sensor reading code. Why is it doing this and how can I stop it? Can anyone please explain? Thanks guys. The car has full bolt ons now and it idles at around 500 rpm. But this time the code came on on the interstate. It doesn't drive any different and it still pulls hard. I did have the O2s spliced but I bought the extensions fearing that the splice might be adding some resistance. I haven't been able to get it reset again but could this be causing the problem? Thanks again.
Staging Lane
Joined: Jul 2002
Posts: 58
Likes: 0
From: englishtown n.j.
Did you install o2 sensors with heaters (rear o2's) in the front location?
Are the heaters wired?
I would rec starting with two new rear o2 sensors in the front position.
clear codes and do 3 starts and small drives.
then post results.
I had slow response with my header/o2's. My tune was on, wiring was right.
Slow response did not effect drivability/power. The light was a problem for inspection. I have a fix if all else checks out. I will post pics and detail if needed.
Are the heaters wired?
I would rec starting with two new rear o2 sensors in the front position.
clear codes and do 3 starts and small drives.
then post results.
I had slow response with my header/o2's. My tune was on, wiring was right.
Slow response did not effect drivability/power. The light was a problem for inspection. I have a fix if all else checks out. I will post pics and detail if needed.
Staging Lane
Joined: Oct 2007
Posts: 60
Likes: 0
From: Lockport,NY
Get yourself 2 Bosch#13111 O2 sensors. They are rear O2s for a vette,they come with longer wires so you can ditch the extensions and they work better on long tubes. I was having the same problem until I installed these. The code is being set because the exhaust is cooler at the new position of the sensor and the O2 sensor needs the exhaust to be really warm to read properly. Thats why you need a rear heated o2s for the front position sensors.
Get yourself 2 Bosch#13111 O2 sensors. They are rear O2s for a vette,they come with longer wires so you can ditch the extensions and they work better on long tubes. I was having the same problem until I installed these. The code is being set because the exhaust is cooler at the new position of the sensor and the O2 sensor needs the exhaust to be really warm to read properly. Thats why you need a rear heated o2s for the front position sensors.
Staging Lane
Joined: Oct 2007
Posts: 60
Likes: 0
From: Lockport,NY
You can get these from any part stores that carry Bosch o2 sensors and if they dont carry Bosch parts then have them crosscheck for what they carry compared to that part#.....I got mine from Advance Auto and Auto Zone,one from each because they both only carried one.
Staging Lane
Joined: Jul 2002
Posts: 58
Likes: 0
From: englishtown n.j.
the bosch 13111 o2's should be the stock rear o2's on your car.
as noted they should be easy to find. I think you need a connector/adapter
in order to power the heater on these o2's when installed in the front position.
Do the extensions you mentioned in you first post have one 4 pin plug?
If not call LG motorsports (supporting vendor) and tell them you need this adapter. this will plug right into the existing plug on the harness and the bosch #13111 o2's. this should end your problem. also check the heater fuse (I don't know the number) this may also be the reason you could not clear the code.
Please let us know your results.
as noted they should be easy to find. I think you need a connector/adapter
in order to power the heater on these o2's when installed in the front position.
Do the extensions you mentioned in you first post have one 4 pin plug?
If not call LG motorsports (supporting vendor) and tell them you need this adapter. this will plug right into the existing plug on the harness and the bosch #13111 o2's. this should end your problem. also check the heater fuse (I don't know the number) this may also be the reason you could not clear the code.
Please let us know your results.
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Staging Lane
Joined: Oct 2007
Posts: 60
Likes: 0
From: Lockport,NY
The 13111 is not the stock rear o2,it is for rear o2 on ls1 vettes, come with a really long wires and plug right into stock connector w/o modding. All o2s are heated on these years not just the rear, it is identical connector just plug it in.Read up on the sticky on the top of the page for the o2 info and fix.
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It probably has something to do with your 02 wiring, asumming the headers aren't just leaking really badly. If the extensions don't fix it, you might just nedd some new 02s. I personally don't have any experience with Bosch O2s, but from what I read lots of people have trouble with them. I've always just stuck with the ACDelco ones form the dealership and I've never had any problems.
Jon
Jon
TECH Resident
Joined: Aug 2003
Posts: 970
Likes: 4
From: England UK
Replace with Bosch 13111's. I just borught a pair for mine andwill install at the weekend. Why did I buy them? My old O2's are 130,000miles old. They have slow response, while driving the appear to switch okay but when on dle they stop occilating and my wide band shows it getting leaner and leaner and engine note changes. I beleive it to be the O2's sitting further down stream (because of LT's) and the done get as hot from exhaust gasses. I've heard great things about the Bosch's O2's expecially for cars with LT's. It seems to have cured a lot of peoples problems. However I have read a few negative responses on this forum too. I'm going to give them a go anyway. I've been resorting to open loop on idle to eliminate the bad reading from the stock o2's.
