joevee1446

I have been reading forums for three days now trying to decide what and how to fix this damn P0402 code. But I'm still unsure. I understand the P0402 code is "excessive EGR flow". However, my 2002 WS6 Firebird has the factory LS6 block and factory LS6 intake with NO EGR system. I have come to the mindset that the A.I.R. system does the same think as the older EGR.

On older F-bodies you could pull the EGR system and clean the valves and the CEL would not come on again nor would you get the P0402 code.

Alot said to ask this question,: Where do I need to start to correct the issue with CEL based on the P0402 code that is setting it off. I understand it does not effect drivability/performance, but I don't want that DAMN yellow light on my instrument panel.

ANY AND ALL HELP WILL BE GREATLY APPRECIATED, before I go blind from reading forums.

2001NBMZ28

You don't have EGR so shouldn't be throwing P0402 - sure it's not P0420? I'd recheck the code.

joevee1446

I have a superchips programer that I'm using to read the DTC. It first tripped the CEL on Thursday afternoon. I used the programer and it showed 1 DTC error P0402. I cleared the DTC but it tripped again about an hour later. Again the programmer showed P0402 and again I cleared it. About 15minutes later it tripped andthe programer showed P0402. Yeterday (8-15-08) it was tripped and rest approximately five times each showing P0402.

Today (8-16-200) I went over the car checking all vacum lines, AIR tubes, fuses, and other connections but did not find anything wrong. Drove the car all night and not once did I get the CEL.

I know the 01 and 02's did not have EGR due to change in the CAM setup. This is the reason I'm complexed and don't know where to start looking for the problem. I'm hoping someone on here has had the same or similiar problems.

The car is basically stock with the exception of a mild CAM, SLP lid, free mods, computer program, MAF screen removed.

Unrelated: but last year code P0400 gave me a FIT for about a month, tripping the CEL 6-8 times a day. Then suddenly it stopped for no known rhyme or reason.

I'm hoping thst maybe this P0402 has "fixed itself"?

I'm open to any suggestions or solution tips.

Thanks in advance to any and everyone that can help in this matter,

2001NBMZ28

That's really strange, I'd try another scanner and see if you get the same code. Has the car ever been tuned?

2xLS1

iTrader: (25)

All 01 and 02 F-body calibrations have P0400 and P0402 set to No Error Reported. No exceptions. If you are setting those codes, then someone has mistakenly turned those codes on in your cal or some other calibration other than a 01 or 02 F-body cal has been loaded in the PCM. You say the car has a computer program for a mod. Who and/or how was that done? With the Superchips?

joevee1446

I bought the SuperChip new directly from the manufacture when I was working for a parts store. I have been the only one to use the programer and it has never been on any other vehicle as this programer has a VIN lock that prevents it from being used on more then one vehicle.

In any case, I drove it today, about 400 miles, and I have not gotten any further SES lights and I just checked the DTC and none exsists. So, I'm good and I want to thank those who responded.