My 03 Ss Detonates !

[SS Tows Can Am]

Hello SS Owners.

I have a drivability problem with my 2003 SS and was hoping someone could help in diagnosing the problem.

My 03 will detonate above 3500 rpm and will sometimes flash the check engine light (misfire condition) for a few seconds. I have run the codes in the computer and they come back to a “Low Efficient Cat on Bank 1”. It will not always set this code.

1) I have been looking at the view data and at 55-60 mph OS1-1 and OS2-1 are reading between .200 and .800. They both are constantly changing with the ST FTRM 1 & 2 changing +/- 3%.

2) OS1-2 and OS2-2 are both reading between .650 and .800. They are constantly changing as well.

3) LT FTRM 2 is reading around 6.5 to 8.0%. Does change.

4) LT FTRM 1 is reading a consistent 0.8%.

 

I have put new AC plugs in, new plug wires and new fuel filter.

Mileage is 107,000 miles.

Truck is stock, no mods.

Premium gas only.

 

If anyone can help troubleshoot or has had a similar problem, please let me know. Thanks

[Fireman31]

Just based on the info you have given, it sounds as if you have a plugged driver's side catalytic converter. The flashing CEL stands for a catalyst damaging random engine misfire(P0300), which can be caused by a plugged or degrading cat(along with the P0420 code you sometimes throw). When that light flashes, you are supposed to pull over and shut the truck down, or severe engine damage can occur(i.e. melt down the entire motor).......

Edited February 12, 2010 by Fireman31 (see edit history)

[SS Tows Can Am]

Just based on the info you have given, it sounds as if you have a plugged driver's side catalytic converter. The flashing CEL stands for a catalyst damaging random engine misfire(P0300), which can be caused by a plugged or degrading cat(along with the P0420 code you sometimes throw). When that light flashes, you are supposed to pull over and shut the truck down, or severe engine damage can occur(i.e. melt down the entire motor).......

Thanks for the info! The thing that was throwing me off was the low reading on the bank 1 LT FTRM.