CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

EGR 402 Excessive Flow

07 6.6L Turbo diesel keeps popping EGR 402 codes. GM cleaning procedure

done ($90). EGR Valve replaced (free). No codes for a couple weeks then

bam… three times in the last week. Reset with code reader each time to

see if it was a stray code or a real problem. So what to do next? The

dealership should be responsible at this point for tracking down the

problem, but apparently they don’t know how.

Is there some kind of solenoid that controls the EGR valve? That’s where I would suspect next. Could be just a flaky connector.

how about the flow sensor itself?