[Trevor]

Originally Posted by 97SVX_SCV

Hello my friends. Cyndee and I own a 1997 Bordeaux LSi, ser #302. She inherited it from her dad who bought it new. it is registered under her name.

I have this problem. The car threw a 'knock sensor circuit malfunction' code. It wasn't knocking and seemed OK so I [please be kind...] ...I stupidly drove it for about 100 miles. it began to run rough, then to barely make it up the hill to home. smelled hot, like the catalytic converters were hot. then would run but just really unpowered.

Situation now- it is a month later and have competed a replacement of the knock sensors and replacement of the PCV and that check valve between the collector and the vacuum tank and a few brittle vacuum hoses whilst I had the collector disassembled, but the car now starts but runs at 3000 rpm for maybe 2 or three seconds then dies. I can keep it going if I feather the throttle but it is way rough and will not keep going at a consistent RPM with a steady throttle input - it has to be feathered or it dies.

I am asking for diagnosis path, really. and considering that this really seems to be a backpressure problem, I want to ask a safe way to first eliminate clogged or failed catalytic converters as the root cause.

Can I safely remove them and check if the relief of backpressure restores idle and throttle response. I know it's going to be noisy. Any perspective is appreciated. thx.

The original knock sensor problem would presumably have resulted in the ECU retarding the ignition during the 100 mile period you ran the car. Commence your diagnosis with this in mind.

Has replacing the knock sensors cleared the code ?