Service engine soon light

LAZYBOOBS2

MEMBER
1998 SATURN SL1
4 CYL
FWD
MANUAL
176,000 MILES

Won't pass inspection. Inspectionsays oxygen something fuel something & something else I don't remember. It failed 3 need to get one to work. Advance & auto zone checks. We have changed the knox(?)Sensor it said first, and also changed spark plugs and cleaned egr valve and ports. Light went off for a short time and came back on. Now auto zone checksays po404 & po405 fault in the egr position & egr pressure sensor, open or short circuit condition. Are there any suggestions you can give us to try? Is there such a thing as egr sensor?Advance auto did not show on their list, maybe it just isn't something they carry? Help please. Thanks for your time.

Tuesday, May 3rd, 2011 AT 10:51 PM

1 Reply

SATURNTECH9

MECHANIC
30,869 POSTS

That sensor is built into the egr valve usually a code p0404 is caused by a dirty sticking valve. But since you also have a P0405 I would diagnose that code I posted the trouble tree for it. You will need a scan tool that can read live engine data to trouble shoot it. You will have to buy or rent a scan tool that can do that or take it somewhere and have them fix it for you. Let me know what you find.

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Tuesday, May 3rd, 2011 AT 11:23 PM