07 check engine light P0403 code

txmike · 08-11-2007, 12:13 PM

started my 07 Classic LBZ this morning and the check engine light came on. It is setting code P0403 which is EGR malfunction. ????

i had to let the truck idle last night for about 2 hours, could this have caused it? Drove home about 30 miles afterward and no problem. truck has 9,000 miles on it. I have to drive it on a 700 mile road trip on Monday and won't be able to get it in to dealer until end of week. I know it is probably minor but will it affect my fuel mileage?

Thanks for advice.

Mike

txmike · 08-23-2007, 10:57 AM

WTF? all the knowledge and experience out here and no replies!!!???

**TYREBOYZ_DEMAXIN** · 08-23-2007, 11:57 AM

sorry about this.my LBZ did the same only after i did a exhaust but when i installed my PPE standard tuner it disabled the EGR..letting it idle for a extended time will build up soot and it can throw codes so thats probalily the cause..

John-Boy 331 · 08-24-2007, 07:53 PM

block it fingure it love it even more

**TYREBOYZ_DEMAXIN** · 08-25-2007, 04:17 AM

question did you do any power adders or exhaust?

DuramaxGuy · 08-28-2007, 10:24 AM

Texas Mike -
Code 403 is for the egr solenoid valve... do you have any aftermarket changes to your engine? The extended idle could have something to do with it, but shouldn't. If your dash light is still on, it is proabably still an active code and you should have your egr valve checked. When you shut down your engine, do you hear the egr valve do some movement for about 10 seconds. If so, your valve is probably okay. It is still working.

rick606 · 08-28-2007, 01:23 PM

My 06 has done the same thing twice and I have taken it in to the dealer and the clear the code and the light comes back on within a 12 hours. The only fix that they have come up with is to replace the EGR valve. The first time was at around 10-12K miles and the second time was about 25K miles. I did not notice any significant change to my fuel mileage this last time (I had to drive about 5 days before I could get it in to the dealer). The big question is, will this continue to happen every 12k or so miles?

dmax500 · 08-28-2007, 10:56 PM

Dont worry this is a common prob. if you dont have any aftermarket exhaust on your truck i.e. strait pipe. ask your dealer if your vehicle applies to the bullitin to reprogram your pcm with an updated calibration for this issue. also be sure to remove any downloads from a flash programer because you wont have it after they program the pcm.

txmike · 08-30-2007, 03:16 PM

thanks guys. my truck is (so far) all stock. I had a 2005 before this one, with Edge/Attitude and Banks cat-back. The 2007 seems to run a lot better than the 05 did stock. so far i just haven't seen the need to change anything. I will probably eventually do a cat-back to keep down the EGT's. Made a 200 degree difference in that 05.

this truck has 12K miles so I am right in line with other guys having this problem. Could part of it be that I have not been exclusively running ULSD? I have a scanner and I think I am gonna reset the code and see if it stays off before I take it in to dealer.

**05_LLY** · 08-30-2007, 03:34 PM

A p0403 would indicate a problem with the valve its self. clear it and if it comes backif it dose i would go see the dealer, you egr valve is probally bad!