98 Malibu, codes P0404, P0405, P1404

[otis24]

Check Engine Light comes on intermittenly on my 98 Malibu (3.1 V6). Stopped by AutoZone and had it scanned. Got codes P0404, P0405, and P1404. All had to do with EGR valve (low voltage, EGR stuck open).

Can the EGR valve be cleaned? What are the effects of running the car with the EGR stuck open?

I will probably replace the valve at some point, but not right away.

 

[eljefino]

Yes they can be cleaned. It should come off fairly easily. Just spray carb cleaner in there and poke the pintle with a screwdriver. Black muck will run out. While it's off, run a shop vac over the holes in the intake to suck up chunks then run the car for 2 seconds. The exhaust should blow out and make noise while the vacuum leak should make it idle high.

If you do nothing, the car will idle and low speed acellerate poorly.

 

[otis24]

Yep, getting the poor acceleration at low speed. Will attempt to clean.

 

[eljefino]

You want the pintle to seal. Sometimes they have little star-drive things you can stick an appropriate driver in to spin, which scrapes the soot off.

 

[beast3300]

No you can't really clean this style egr. Replace it.

 

[eljefino]

I beg to differ; I have cleaned this style. Sometimes just jarring it will pop the pintle back home.

Cost $0 and ten minutes. Might last a year!

 

[NHGUY]

Thats an electronic EGR,usually the electricals go bad.

 

[beast3300]

Originally Posted By: eljefino

I beg to differ; I have cleaned this style. Sometimes just jarring it will pop the pintle back home.

Cost $0 and ten minutes. Might last a year!


I'm sure you have but respectfully speaking, it will not fix the problem. Cleaning the egr passage will fix an insufficient flow code on a 3100/3400 gm product though. (Common also)

 

[Merkava_4]

If you hooked up a GM Tech II scanner to your diagnostic port, it would tell you the pintle position in percentage of opening depending on what your RPM is. At idle it's supposed to be 0% open with an increasing percentage as you come off idle. On my Buick, the EGR pintle position was at 0% all the time no matter what the throttle position was. After back-probing the connector and making sure the EGR valve was getting the reference voltage it needed and sending a signal voltage back to the PCM, the EGR valve was then determined to have a burnt out solenoid.