Tail pipes

[Trek-Cyclist]

After changing the oil/lube I noticed the drivers side pipe was blacker then the pass.side..
A Workhorse shop replaced the anti-knock sensor on the DS last spring... Could this have something to do with it? I can't see having different timing for the right and left side of the motor...???
I'm not going to worry about it just wondering if someone has an idea

[Trek-Cyclist]

After changing the oil/lube I noticed the drivers side pipe was blacker then the pass.side..
A Workhorse shop replaced the anti-knock sensor on the DS last spring... Could this have something to do with it? I can't see having different timing for the right and left side of the motor...???
I'm not going to worry about it just wondering if someone has an idea

[Mutha]

Ed, It could be you have a loose/leaking donut gasket that connects the right side engine exhaust manifold outlet and the right side header pipe inlet. Outside air being sucked into the leaking connection can cause the right side Qxygen Sensor to read lean and call for more fuel to the Right engine bank. This would cause your tail pipe soot to be much greater in the right exhaust tail pipe.
I do not beleive the knock sensor would cause a rich condition in only one side of the engine, as it is primairily for timing control and not fuel mixture.
If you have a nearby chevy truck dealer that can read your ECM DATA with a scan gauge, it will show any Oxygen sensor faults, or any other faults for that matter. Most dealers charge about $75 for just a diagnostic scan, and it may be well worth it to head off any serious engine damage.

Good luck - Glenn

[Tenn.Vol.]

Ed, my Liberty turned the SES lite on around 60K miles or so..
I checked the code with the Scan Gauge II and called my ASE master MO.
He looked up the code and said one of the front o2 senser..(2 in front of
cat 2 in rear of cat) He said to change them in PAIRS so I did. The dealer
would have changed the bad one but not both. I did not even WANT to go there!
After he explained the reason why, I had no problem with changing both. TENN.

[Trek-Cyclist]

Thanks for the information...
I checked again this morning just to make sure and they were the same however when we get to Mesa,AZ for the winter I'll have it all checked over just in case..??
Right now ee're struggling with trading up or not... The issue for us is we know what we have its been good to us, but we don't know what we might get...we kind of like the room/floor plane and storage the Phaeton 40 quad has... well see..
Again, that for the info..