I'm starting to think I have a problem. Despite having two perfectly good cars, I couldn't pass up a cheap 95 A4 Z28 with a fried trans. I towed it 80 miles home and it's been sitting in the carport being treated to junkyard trim and such.

While I'm figuring out how to finance the transmission, I've been working on the SES light. Evidently it's been on since the previous owner had the engine rebuilt.

So...the new engine has about 4k miles on it, rebuilt bottom end, Edelbrock heads, headers, TB, Moroso CAI, MSD ignition, Borla catback, ?traction bars, a cam that the previous owner called an LT4 hotcam, and the custom tune that the shop which installed the engine put in.

The previous owner gave me some receipts with the car. One of them shows a Kragen ECC 71 6523 Knock Sensor which he installed. The SES light was on from the moment I picked up the car. So the first thing I checked was the knock module. It was pn 16177700, but was replaced with the LT4 module I happened to have sitting around pn 16214681.

So the car is still throwing code 43... That wouldn't be a big deal, but to pass California emissions, the SES can't be on. I could always reprogram the PCM to eliminate 43, but I'd rather fix this right. Any thoughts?

 

The knock sensor and the knock module are two different things. It seems you are thinking they are the same.

 

He might have bought the wrong knock sensor. If the resistance is not right, the computer will read it wrong.

 

I'll have to check the knock sensor. That's a good idea... Any ideas on what the resistance should be?

And, I didn't think the two were the same. The previous owner changed the sensor. I changed the LT1 module for the LT4 module. Any other thoughts on this?

 

You need to get a service manual for the car and follow the steps of testing the sensor and wiring, a code 43 doesn't always mean the sensor it self is bad, it would be an issue with the wiring to the sensor. I had the same issue but mines ended up being a bad sensor.

 

Problem solved...maybe

I talked to the part store and they checked the pn from the receipt. Turns out that the previous owner put in a OBDII knock sensor. Thanks for the help guys.