EGR Low Flow, Code 332

[sam]

I have a 94 B3000 which threw a 332 code, Low EGR Flow. 211,000 miles. After searching the posts, I replaced the DPFE sensor (new). I drove it and the code re-appeared. I checked the EGR valve and it seemed to function OK, and was not all carboned up. I verified all the vacuum lines were ok and that I had vacuum on the hose to the EVR. Still throws a 332 code.

I replaced the EVR with one of an unknown condition (out of a ranger with 126,000 mi), still throws the code.

I replaced the EGR tube (out of a ranger with 126,000 mi), still throws the code.

Is this a vehicle I need to disconnect the battery on to erase the code (ODBI)? The light does not go on until the vehicle is warmed up and being driven, and not before.

Sam

 

[sam]

Well, I found the issue with my 3.0L EGR system. I ran a key on engine running while monitoring the vacuum signal from the EVR to the EGR. Everything worked just as it was supposed to pointing some obstruction in the exhaust flow to the intake. I found the intake so crapped up with carbon that I got no flow. Thus, the computer didn't get any feedback from the DPFE and gave a code (332, low EGR flow). I pulled the EGR and there was no vacuum when the engine was running again pointing to the intake.

I managed to get the chunks of carbon out, and freed up the passage and get good strong flow now. Highway test with no codes.

This engine had 211,000 miles on it and I guess the stuff just built up over time. PITA to get out, about 4 hours of trying everything including a rifle cleaning kit.

Sam