1998 4-Cyl auto trans 225,000 miles

Just got done cleaning the upper intake for a P0401 code. The next day P1491 (Exhaust Gas Recirculation Valve Insufficient Lift) pops up. No rough idling or other noticable issues. I cleared the code and its been 24 hours.

When I took the Upper Intake off to clean the ERG port, I also removed the EGR valve to clean the passage between the EGR valve and the Upper Intake plenum. Most of the gunk was on the Intake Plenum itself. I took an air hose and blew out the passage.

While the EGR was off, cleaned the EGR valve just a little- it didn't look bad at all. I also tried to push on the stopper valve and it didn't move. I work on GM cars and you can push the stopper back a little (using the eraser end of a pencil). I decided maybe it was made different and put it back on.

On-line, I see 2 options
1) clean the EGR ports- I doubt I want to do this again!
2) replace the EGR valve.

If the P1491 comes back... replace the EGR valve is the next step?

Or is there other quirky things that can happen and cause P1491?

 

This code occurs when EGR is commanded to open and no or insufficient EGR valve lift feedback was detected. This could be damaged EGR valve or wiring fault on valve drive circuit.

Suggest checking wiring for integrity and if OK, then replace EGR valve. You could also remove EGR valve, rig a direct 12v drive to the EGR connector and see if valve will open w/ direct voltage applied. Diagnostic for P1491 is attached.

good luck

 

Thank you... will check when I get home -or the next time the SEL comes on again.