polorico

Hey whats up guys , I just had my ls1 rebuilt with pacesetter 1 3/4th longtubes , forged internals, 317 heads milled and ported , and a small 224r 114LSA cam , and a texas speed mail order tune.

I Have had the car for about 3 weeks, I have about 400 miles on the fresh motor rebuild.

At first the Service engine light would come on with a PO0327, and PO332 codes (knock sensors) . When I clearanced my headers the code went away. I had the pipe that was hitting refit and bent down away from the frame by an exhaust shop. I now have no type of hitting upon acceleration , only when it is cold started can I hear the header knock against the under carriage .

So my SES light came back on yesterday ,It pulled a mis fire code that I have never had before. Mind you the motor has less than 500 miles on it. So i parked the 00 z28 over night.. I checked the codes again today and I pulled the two knock sensor codes again , PO0327, and PO332 but this time I also pulled PO135, PO155 (02) sensors no miss fire code came up this morning. I can smell that the car is running rich.. Not horribly bad but i can tell the difference in smell from when I first picked up my vehicle after the rebuild .

I have read that long tube headers can cause (02) sensors to act crazy and even throw a miss fire code. My plan of action is to order the densco sensors (part number 234-4617) with the 44'' wire ..

Quick questions , Does this need to be addressed ASAP ? I have read that the densco sensors have fixed this issue with bad 02s. The thing that puzzles me is the knock sensor. Could they both just be worn out ? I also have read that a dyno tune done by an experienced ls1 tuner can take care of these problems

00Vette04GTO

I am NO expert here, but I will give you my thoughts until someone more knowledgeable steps in....

P0332 and P0327 are low voltage on the knock sensors. These are not normal codes to be thrown after doing an engine swap or other upgrade. Could they have left them unplugged? My guess is they did. They are under your intake, which is fairly easy to disassemble.

P0135 and P0155 are heater element codes in the O2s... Almost sounds like they didnt hook them up? Tho you should get another code for that. My guess, melted wires?

I'd be going back to that shop!
-Mike

polorico

That's what I was thinking also, Should I wait before I pull the trigger on parts?

I am just concerned that running rich will cause me to mess up the break in process. Gas mileage doesn't seem any different, no black around the tips of the exhaust nothing unusual outside of a small smell.

Matt@SNLPerformance

iTrader: (1)

Check to make sure that your harness has not been pinched between the rear of the block and the bellhousing. As always check your fuses just to be sure.

texashavoc

Tech 2 should tell you all

polorico

Got the vehicle back today. It doesn't smell like exhaust n the Caban anymore . Car showed no codes upon pick up. I also had my exhaust clearenced. After roughly 60 miles my SES light unfortunately returned. I pulled the codes and they are 332 , 337. Dang knock sensor codes. Car runs great so far I just don't know what is causing this knock sensor light on a build with 500 miles. Would the smart thing to do is replace both asap ? I am hoping this not the start of a massive money pit. Also should the knock sensors be covered under warranty? Thanks.

polorico

I used bosh 02 sensors to replace the bad 02s.


Tried to start my car for work today and I could not get it to start and idle. Had to tap the gas slightly . Car idled fine ,and I made it to work. Could the knock sensors cause the car not to fire up quickly on a cold start?

2xLS1

iTrader: (25)

Did you use AC/Delco knock sensors and install them with a Tq wrench torqued to 15 ft lbs?

CIRCUIT DESCRIPTION
The Knock Sensor (KS) system detects engine pre-detonation. The PCM retards the spark timing based on the signals from the knock sensors. The knock sensors produce an AC voltage when specific frequencies are detected. The knock sensor voltages are an input to the PCM. The amount of AC voltage produced is proportional to the intensity of the knock.

An operating engine produces a normal amount of engine mechanical vibration (noise). The knock sensors produce an AC voltage signal from this noise. When an engine operates, the PCM learns the minimum and maximum frequency of the noise the engine produces. When the PCM determines that this frequency is less than or greater than the expected amount, a knock sensor DTC will set.

CONDITIONS FOR RUNNING THE DTC


•The engine speed is between 1,650 RPM and 3,000 RPM.
•The MAP is more than 49 kPa.
•The engine coolant temperature is more than 60°C (135°F).
•The throttle angle is greater than 0.5 percent.
•The engine run time is more than 20 seconds.
CONDITIONS FOR SETTING THE DTC
The PCM determines that this frequency is less than or more than the expected amount for less than 3 seconds.

polorico

Car started up fine at lunch hour today, it warmed up around 15 degrees.

Update , I called LG motorsports and told the customer service rep my situation with my build. Around 500 miles on the new motor 317 heads ,224 cam ,mail order tune .I asked their opinion on why the codes would trigger the SES , and if they had any experience with this issue. He told me they would need 3 hours to evaluate the vehicle, and that it could be an exhaust clearance issue , or that the sensors , and harness could be bad. Which would run 300 bucks just to see what the issue is on my 2000 z28.

I have not even checked the sensors or wire harness. I am going to go ahead and order the Dorman 917-033 Knock Sensor Harness , and 2 ACDelco 213-3521 OE Service Knock (Detonation) Sensor. Going to take my time and make sure the wires , and everything is smooth and not pinched upon installation. I am going to go head and order all 3 parts. My inspection is coming up next month and I'm low on money until September. I'm starting the think I need to get the car dyno tuned by a reputable tuner. I have read a good tune fixes a lot of issues with builds with over 400rwhp . I am hoping that this will fix this issue , and that it is not the beginning of a ghost in the shell money pit.

Slowhawk

iTrader: (12)

We can guess a lot. Just really needs a good shop with tuning skills and can read /log files from the car.

polorico

Very true Slowhawk ,

Would the first step in the right direction be swapping out the old sensors and harness with new ones , and hope that fixes the issue ? I am just going by what my codes said. Thats why i am crossing my fingers hoping this is not a ghost in the shell issue.. If it was in the fall I would just take my car down to Quality motorsports and have them get to the bottom of it. I was hoping to use this money for suspension ,and tires ... I wanted to hold off on a good dyno tune until I upgrade my Intake.. This car needs to be my DD . I am a college student .. So sometimes I can not afford to not have my vehicle for days at a time.

Skidog5150

iTrader: (2)

Did you ever find out what the problem was that was causing the codes??

polorico

Havent yet , I am taking the car in as soon as i get some money in. will update thread in a week or two.