LS1GTO Forums banner

1 - 20 of 44 Posts

·
Registered
Joined
·
1,028 Posts
Discussion Starter · #1 ·
I just got my car tuned by a reputable tuner locally and I'm completely happy with his work. He spent ~2hrs with my car, then we drove around while he logged it for about 20 minutes. Shortly after I left, I stopped at the grocery store and noticed the CEL was on. I switched over to my Torque App and it shows the following:

Current fault: PO327 Knock Sensor 1 Circuit Low Input (Bank 1 or single sensor)
Pending fault: PO332 Knock Sensor 2 Circuit Low Input (Bank 2)

I cleared the code and it came right back. I emailed the tuner and he asked me to at least look at the wiring and sensor, to make sure I had no melted wires or damage. I plan to do that tomorrow. In the interim, I pulled the neg battery cable last night, and drove it about 10 miles today, and then the code came back again. I also could not clear it. About an hour ago, I started it up cold, and the CEL was off, but I suspect it would come back if I drove it much.

I've been researching this like crazy because a CEL bugs me. I do want to take it back to him, after I do a courtesy check that there's nothing wrong with the sensor or wiring. It's just too much of a coincidence that it threw a code not even an hour after I left the shop.

In my research, I've seen a couple of options:
  • Turn off the DTCs for these codes. It will still detect knock, it just wont throw these specific codes.
  • Have him go back through all of the sensitivity/gain sections of the knock sensor and trial/error it until its fixed.

I only have the Torque App on my phone, so I can't really look at the tune, but I do want to go back with more than "Its broke" when I see him again.

Can someone speak to this issue, if you've run into it, and provide a suggestion? It seems pretty common but the solutions (in HPTuners) vary alot.

Thanks in advance..
 

·
Administrator
Joined
·
20,873 Posts
Check the wiring. Something got melted or disconnected.

For the love of god dont just turn off DTC's for knock codes. Thats like turning off your pain sensors while you stab yourself with a screwdriver.

"THIS IS FUN"
 
  • Like
Reactions: BroPeep

·
Registered
Joined
·
1,028 Posts
Discussion Starter · #5 ·
Based on the replies, I will get under the car and inspect the wiring. To me, it seems to a very low chance of being the cause. I have done no major work to the car and the JBA Shorty headers have been on there for over 3 years. I'll report back.
 

·
Administrator
Joined
·
20,873 Posts
Maybe it is a low chance but that's what the fucking codes mean. Yes, the ECM could be bad, or maybe you have a low votage condition or something of low probablity, but troubleshooting best practice is go for the high-probability low hanging fruit first.
 

·
Registered
Joined
·
516 Posts
I had the same issue, they would randomly pop up after driving the car for a bit. I traced out the wiring and everything seemed fine on it, I did have an issue where my alternator died and drained me down so I wonder if that voltage dropped threw something off.

I turned em off in HP Tuners, it's a NA motor running E85 so I am not concerned. Many other LS guys turn the KS's off on their built cars too.
 

·
Administrator
Joined
·
20,873 Posts
Many other LS guys turn the KS's off on their built cars too.
Those guys are stupid, but whatever, FPFQ grows over time

edit:
dont know why I am salty this morning
 

·
Registered
Joined
·
1,028 Posts
Discussion Starter · #9 ·
To be clear, I'm not asking about turning off the knock sensor itself - that is stupid - but the trouble or diagnostic code, as discussed on the HPTuners forum. Link
 

·
Administrator
Joined
·
20,873 Posts
I get it, but its still dumb. You wouldn't turn it off unless it was throwing the code, which means theres a problem with knock, and ignoring it is stupid
 

·
1 of 40,757
Joined
·
6,647 Posts
The sensor wires on the drivers side of the engine is susceptible to being pinched or melted by LT's.
Survived on my car for quite some time before finally melting through and throwing a code.

With that said, bank 1 and 2 at the same time is a bit suspicious.
 

·
Premium Member
Joined
·
1,576 Posts
i dont think thered be any reason to change the stock knock settings on a stock engine (no cam). am i right in thinking this? cant imagine getting much false knock.
 

·
Administrator
Joined
·
20,873 Posts
i dont think thered be any reason to change the stock knock settings on a stock engine (no cam). am i right in thinking this? cant imagine getting much false knock.
Sometimes you change the burst knock values in the tune in forced induction applications because its basically "predicted knock". You have to be careful though and make sure you dont get real knock after fudging with it.

But in general no, you dont need to change knock values really ever, unless you are hiding something (cheap-ass tuners)
 

·
Premium Member
Joined
·
1,576 Posts
Sometimes you change the burst knock values in the tune in forced induction applications because its basically "predicted knock". You have to be careful though and make sure you dont get real knock after fudging with it.

But in general no, you dont need to change knock values really ever, unless you are hiding something (cheap-ass tuners)
thats what i thought. didnt know about the burst
I think sacrifice might be thinking of the cylinder misfire tables. Those you do have to fiddle with.
no i was talking about spark-retard

theres a couple descriptions pertaining to the codes he is getting. just thoughts out of my ass without a tune to look at
 

·
Registered
Joined
·
516 Posts
I get it, but its still dumb. You wouldn't turn it off unless it was throwing the code, which means theres a problem with knock, and ignoring it is stupid
because those codes are popping up does not at all indicate there is a knock problem.

Yup the guys I know that turn em off are stupid and FPFQ, that's why they all reliably make 4 digit power numbers
 

·
Administrator
Joined
·
20,873 Posts
because those codes are popping up does not at all indicate there is a knock problem.

Yup the guys I know that turn em off are stupid and FPFQ, that's why they all reliably make 4 digit power numbers
I RACE CARS WITHOUT SEATS BEATS AND HELMETS BECAUSE I HAVEN'T DIED YET LOL LOL LOL
 

·
Registered
Joined
·
1,028 Posts
Discussion Starter · #18 ·
I put the front up on ramps, pulled off the skid plate and ran my hands along both sensors and harnesses. Then I looked down at the loom from the top, where the bell housing meets the engine. It's all perfectly clean and flawless. I have at least 5 inches of clearance from the exhaust to the wiring. There is nothing physically wrong to be found.

Right afterwards, I drove it about 40 miles into the next city, stopping 4-5 times over the course of 3 hours while running errands - No CEL. On the last segment, about 8 miles from home the same two codes lit the CEL. Whatever the cause, its truly intermittent. Slowing cruising, hard acceleration, highway speeds and stuck in traffic with rising temps - none of it triggered it.
 

·
Registered
Joined
·
516 Posts
I put the front up on ramps, pulled off the skid plate and ran my hands along both sensors and harnesses. Then I looked down at the loom from the top, where the bell housing meets the engine. It's all perfectly clean and flawless. I have at least 5 inches of clearance from the exhaust to the wiring. There is nothing physically wrong to be found.

Right afterwards, I drove it about 40 miles into the next city, stopping 4-5 times over the course of 3 hours while running errands - No CEL. On the last segment, about 8 miles from home the same two codes lit the CEL. Whatever the cause, its truly intermittent. Slowing cruising, hard acceleration, highway speeds and stuck in traffic with rising temps - none of it triggered it.
That's how mine is/was
 
1 - 20 of 44 Posts
Top