First time posting. I hope I will explain the issue well. 2008 Sahara Wrangler Unlimited w/ 3.8L V6. I took it into the shop to have the head gasket replaced and the valve cover gaskets as well. The work was completed but the mechanic said he suspected that the catalytic converter on the driver's side was clogged. I took it home and ran it for a while and checked the cats with a thermogun and the passenger side was 350ish and the driver's side was 600ish. So i determined that I need to replace that cat. I ordered an entire new system starting from the manifold all the way to end including the muffler. I also replaced all four O2 sensors. After installing I reset everything and all seemed to be good until the check engine light came on. I had it checked and it was reading high voltage on the downstream driver's side. I took it back to the shop and asked them to confirm my suspensions and if it was right, replace the sensor. He got the same reading when he checked it. However when he replaced the sensor it didn't fix the problem. He then replaced the cam shaft position sensor and connection and the spark plugs and nothing changed. He has 35 years experience and said this has never happened. He spent two days trying different scenarios and still the same engine light with the same code. I tried the original sensors that I took out and still have the code. Nothing we've tried seems to work. Any suggestions?
O2 Sensor issue
- Thread starter Hardware man
- Start date
Were the new Cats OEM if not then that would be throwing a code, or is it just one side doing the code. What Brand of O2's were used?
Was there a ECM reset done?
Was there a ECM reset done?
No the cats were aftermarket. Yea just one side and only the down stream. I’m pretty sure they’ were NGK?
If they are aftermarket you may need to do O2 Foolers like I had to do with my High Flow Cats. Read this link I gave you.
EOS Exhaust J Style O2 Performance Oxygen Sensors Restrictor
The exhaust oxygen (O2) sensor is a device that measures the amount of oxygen in the exhaust gases produced by an internal combustion engine. The O2 sensor is positioned in the exhaust system, typically before the catalytic converter, and sends signals to the engine control module (ECM) to...
eosexhaust.com
If they are aftermarket you may need to do O2 Foolers like I had to do with my High Flow Cats. Read this link I gave you.
EOS Exhaust J Style O2 Performance Oxygen Sensors Restrictor
The exhaust oxygen (O2) sensor is a device that measures the amount of oxygen in the exhaust gases produced by an internal combustion engine. The O2 sensor is positioned in the exhaust system, typically before the catalytic converter, and sends signals to the engine control module (ECM) to...eosexhaust.com
Would i use these on all four sensors or just the one that is giving me the code? Have you had any issues since installing them?
Only the down stream, but I find it hard that only 1 of them is causing a problem. I can't guarantee this will be your fix, but if the Cats weren't OEM it's a good chance it will fix it. If it was me i'd go ahead and but 2 of them just in case.
No issues since installing them either.