Possible bad Knock Sensor
Thread Starter
Advanced
Joined: Sep 2017
Posts: 72
Likes: 0
From: Kalkaska MI
Possible bad Knock Sensor
First let me say hi as I am a new member and appreciate all your help and expertise.
I have a C4 88' all stock with 98k miles. I was getting the dreaded SES lite, it would come on for a few minutes and then go out. It seem to come on just as the engine bucked or missed (Slightly)... a few times and then would smooth out. I had it looked at by a local trusted mechanic and the didn't get any codes. I had a fuel injector system flush done thinking it was carboned up and I had not had one done in a few years. They did see evidence of carbon build up. But a few days later the SES can on again and this time stayed on, AND the engine was running rough, like it was only hitting on 7 cyl. A code check showed 42 & 43.
From what I've read, code 43 could be a bad knock sensor. My question, would a bad knock sensor cause the engine to run rough?
I have a C4 88' all stock with 98k miles. I was getting the dreaded SES lite, it would come on for a few minutes and then go out. It seem to come on just as the engine bucked or missed (Slightly)... a few times and then would smooth out. I had it looked at by a local trusted mechanic and the didn't get any codes. I had a fuel injector system flush done thinking it was carboned up and I had not had one done in a few years. They did see evidence of carbon build up. But a few days later the SES can on again and this time stayed on, AND the engine was running rough, like it was only hitting on 7 cyl. A code check showed 42 & 43.
From what I've read, code 43 could be a bad knock sensor. My question, would a bad knock sensor cause the engine to run rough?
Le Mans Master
Joined: Aug 2015
Posts: 6,090
Likes: 1,972
From: St. Charles MO
Those codes can mean different things on different year C4s. You need to find from a factory service what they mean for you. I _think_ that it may refer to your ignition module on your earlier car, whereas on my 1996 code 42 does refer to the knock sensor. I know on my car if the knock sensor or module fails, it just retards the timing. The engine actually runs smoother but is sluggish. It sounds like your problem is different.
