U Bend/Res/Muffler delete

**Sabrewings** · 11-01-2008

Originally Posted by bluegtp91

Basically Knock Retard causes predetonation in the cylinders, causing one or more of your pistons to top out and smack the piss out of the head. Which leads to it chipping, or in my case, shattering the skirt

KR does not cause detonation. It is the engine's response to detonation to protect itself.

**98GT3800** · 11-01-2008

That helps. I just didnt know what the KR had to do with the u-bend and no cat. but i guess its from the o2 sensor code. Apparently unplugging the sensor is better than having a bad sensor. Like i said before i lost so much mileage with the sensor plugged in and no CAT, Im guessing the car was running rich. (my guess) So today i unplugged before i left and ran around doing my errands, and its back to normal. Does that make sense, unplugged or no o2 is better than one still running without the cat...