93z383

iTrader: (-1)

My car is a 97 z28 M6 30th anniversary

So I've been going batshit crazy for the last month trying to figure out this "knock sensor 2 low input" code I've been getting.. and I think I just found out why. The code never shows as a primary in the scanner and never turns the SES on, it only shows up in "enhanced DTC's" when you dig for it. I have been getting a bad low rpm miss and can't go WOT without the car breaking up on me, haven't been able to have any fun for so long.

So I bought a LT4 knock module thinking it would help, I'm also installing LT headers so figured why not, I'll grab one. Pulled the PCM and saw the yellow junkyard marker T/A written on my PCM... -_- "****" I said.

Pulled out the knock module, and the part number is 16177700, which is a 94-95 ONLY module, right? The numbers on the PCM are 16239920 and 16242921, which showed 94-95 pcm.... would a KS of the wrong year cause retard and negative effects?

This is bizarre considering my car is 100% bone stock... I'm wondering if the previous owner had problems and though all the PCM's were the same. I mean the car ran flawlessly when I bought it... This code and misfire only began happening when I physically pulled the KS out to flush the coolant, for some reason it was fine before.

I've also been having problems with my fans not turning on until the car is 3/4 up on the temp gauge near overheating, and my "low oil" light frequently comes on as well with no oil problems in the car. Is all this attributed to this mixed up PCM, or what issues are/aren't?

Is this a bad thing, or is everything the same and all I need is a 94-95 knock sensor? Somebody please help me out and walk me through the differences and what I need to do... I'm also getting the car tuned (was supposed to...) this week and now I don't know what to do.

Bigtoyz

iTrader: (2)

Look in his link I believe this is your answer. I was thinking it was but wasnt forsure so I did some looking.

https://ls1tech.com/forums/lt1-lt4-m...obd1-swap.html

edcmat-l1

iTrader: (10)

The breaking up is probably the Opti. None of your problems sound like they're resulting from the PCM swap. People have been doing that PCM swap for years now.

93z383

iTrader: (-1)

How wouldn't that cause problems? I have a 94-95 pcm in my 97, and don't have the matching 94-95 knock sensor. That's what was causing alllll my problems, misfire, breaking up (pulling timing) at WOT, and the KS code for bank 2 low input because it was the complete wrong KS.

I put in the LT4 knock module and it seems to have fixed it, but I still want to go out and get the proper knock sensor. Right after I put the LT4 KM in the car felt instantly better, no misfire anywhere, super smooth, and I could go WOT, smooth and perfect.

See I don't know if now that I have the LT4 KM if it doesn't matter what knock sensor is used since the LT4 KM works with all LT1's, but the knock sensor is still a 97 one paired with the 94-95 PCM.

My main question though is should I just keep this oddball PCM in the car? And is there anything else I need to change in order for this to work flawlessly with my car since everything in it is 97 and not 94-95 like the PCM is expecting? I know 99% of everything is the same, but I also know some things are different.

I wanted to get a dyno tune after I did my headers this week... so when I go in to the tuners, do I tell them they need to tune for 94-95?

93z383

iTrader: (-1)

Bump..

So last night the car felt great after I put the LT4 KM in... I went out and got the proper knock sensor (94-95) today and put it in, and now the car is running like **** again... the sensor I pulled out was indeed a 97 sensor which should have been wrong for the 94-95 PCM...

Also is the knock sensor supposed to thread all the way in, then torque to 14lbs, or should I pretty much thread it in by hand and as soon as the torque wrench clicks at 14lbs should I stop? It's pretty tough to thread it in and seems like it takes more than 14lbs just to get it threaded down all the way, not cross threaded either.

OutrunNAScaR14

iTrader: (4)

Bump... You send my cutout yet? Or did you just take my money and run. It's been two months and I have the message where you said you got the money. Now send my cutout or send me my money back.

jtotheizzo

The main reason people swap those PCM's is so they can tune them because there is a limited amount of software available for the obdII LT cars mainly in the logging department. I would say that it is very likely that nothing will be what it seems on that car. If I was you I would take it to the tuner and tell them all you know. I am sure they can aid you in getting it setup correctly. As far as the differences in knock sensors; in general they are just tuned to react to a certain frequency. The LT4 modules are in essence a little less sensitive than some of the others. Again if I was you I would have that thing tuned by a professional before you hurt it if it is indeed getting real knock.