Ok, so after over a month of being without my car due to rearend issues, and having a new master fabbed up for my p.o.s. textralia problem, I got my car back last night. I test drove it before trailering it home, and no problems occured. I got home, unloaded it, and decided to go for a little joy ride. No more than a 1/4 mile of normal driving and the SES comes on. I go back home and check the codes and have PO327. I clear it, and continue to drive for several miles, some normal, some full throttle, before it comes back on. This time when I checked, I had PO327 and PO332 (knock sensor circuits low input). So I'm not an expert, but the car was retuned while at the shop because I had never had it reflashed for the Mamo FAST 90 I had put on. It seems to me like maybe the tune could be causing this. The car seems to run strong, and the best I can tell from driving it, I'm not gettin any sound of knock. Any ideas? I'm beyond pissed because my car has been down for like 6 weeks from various problems, so to finally get it back and get this...
Any help will be greatly appreciated!

 

Possibly forgot to plug the Knock sensors back in (at the car harness side) during the intake swap?

 

Would that not have shown up during the street/dyno tune? Do you mean where it plugs into the pcm, or is it under the intake ( I didn't do the swap myself)? Please let me know, I will gladly pull the intake or the pcm to check if it that is a possibility! Thanks for the info!!!

 

The KS harness comes out from under the intake rear/passenger side. I'd see if it's plugged in first before pulling the intake. Look up the codes at gearchatter.com for your year on how to troubleshoot the sensor(s) side.

 

Or it got nicked and is shorting to ground.

 

Thanks guys!!! I'm bout to head home and check it out. Hopefully it is something simple, I really hate to have to drive back to PCM For Less for another tune! Atleast its not something that will hurt the engine, it doesn't seem to be actually knocking, so I guess the situation could be worse!

 

Its not a tune issue. Its a problem with the circuit. You cant tune it, mis-tune it, nothing. Its not tune-able. Its a circuit problem totally unrelated. Most likely a burned wire from the headers, or the connector not connected, or pinched wired pulling it to ground, etc.

 

I chased this same problem for months in my Fbody.

I would get the codes at part throttle just cruising...no KR anywhere.
After logging the crap out of it, and determining there was no KR, I started working on it with a good fried of mine who is a GM tech.
As soon as I told him what was happening, he tells me to change out my MAP sensor....what?
He said he has chased the same issue on several cars, and always fixes it by swapping to a new MAP sensor...so...I took one off his Vette and what do you know? Haven't seen these codes in like 1.5 years now....

Good luck with it.

 

Wow, good advice guys!!! I just thought it was kinda convinient that before I took the car to have my 9" worked on, nothing showed up, but after the tune it did. But I trust your opinions since most of you seem to be speaking from experience! So, I have never messed with a map sensor before, but maybe I can find one this afternoon and start workin' this weekend! I didn't find anything unplugged behind the intake, I might need to check for burnt wires though, but I haven't noticed any while workin so far. If all else fails I'll pull the intake to check the wires, but I think they should be fine, I had driven the car around 50 miles after the intake swap, and while the rear end and master cylider were being fixed, it was test driven, then street tuned with no codes. Would the damaged wires have shown up by then? Anyway, I'll keep you guys posted on what I find. Thanks again!!!

 

Well, I tried the MAP sensor this weekend. I changed it Saturday, drove it off and on all afternoon, totalling about 65 miles. Then drove it around a little while Sunday afternoon, but the code came back!!! So I guess it must be something else....

 

Bummer.
Check all of the harness connections like others mentioned, I'm sure something will stand out.

Good luck.

 

It has to be either the wire (disconnected or damaged) or both knock sensors are dead. It seems pretty unlikely that both KSs would crap out at the same time so I'm guessing the wire.

 

Well, I did some research and found that the '98s have problems with the knock sensors, so I ordered two of the 99 & up upgraded sensors and the adaptor harness to see if that is the problem. I hope to have it done this weekend, just as soon as the parts come in.

 

Not trying to hijack your thread but I have the EXACT! Same problem I had tick performance install a fast 92 intake manifold and then the car was tuned by Pcm for less and about 300 miles later the ses light came on with these exact same codes bank 1 knock sensor low imput and bank 2 knock sensor low imput I've checked all the connections and changed both knock sensors and the wireing harness is flawless the same codes just keep coming on over and over if you figure out the solution please let me know thanks

 

Wow, that kinda makes me wonder if it might actually be something in the tune. I changed both sensors, and the wire last week. I wraped a butt load of electrical tape around the wires just for added safety before I put it all back together. I put around 100 miles on the car, and the light has not came back yet. I had a bad connection on my battery yesterday and had to fix that, so the computer has probably reset itself agian, so I'm gonna just keep driving to see if they come back. If the codes do return, the only thing it could be would be a tuning issue right?

 

No, as Ed already mentioned, this is *not* something in the programming.

Usually when I see this after an intake swap, the wires were crushed and fail shortly thereafter...

 

how did it go ?


was the problem solved ?

 

Well, so far the light has stayed off. The wires were a little flattened, but not to a point that I think it would be a problem. But I switched to the 99+ knock sensors and a new wiring harness, so I should be set. I'll post back up if anything changes in the next few miles!