1. Home
  2. General Motors Forum
  3. check engine soon light

check engine soon light

Hi I have a 90 cavalier Z24 that the check engine light keeps coming on. It throws one code which is 33. I was told that it was the egr valve so I replaced it . The thing is electronic and pretty expensive. Also I tuned it up new plugs ,wires, coil pack pcv valve,all the filters and a oil change. The car runs great but again the check engine soon light came back on and again a 33 code. In PA the car will not pass emissions with the check engine light on. The car has a 3.1 engine and 165000 miles. Any help would be appreciated.

Reply to
den630
Loading thread data ...

Check for broken wires in the harness that goes to the EGR valve. The wires are only about 20ga. and pretty fragile.

I see it quite often...

Reply to
Neil Nelson

You might want to look up gm error code 33. It is for map sensor high, not egr.

Reply to
=?x-user-defined?Q?=AB?= Paul =?x-user-defined?Q?=BB?=

Reply to
den630

The EGR passages in the manifold could be clogged and preventing enough flow from going through.

Reply to
Robert Hancock

When you had the EGR off did you notice if the passages were clear?

Reply to
D F Bonnett

Yes I did ,I disconnected the flexible hose that goes to the exhaust pipe to see if it was clogged it had some carbon inside but not much. I also checked the intake where the valve mounts to the engine again it some carbon buildup so I used a coat hanger and rag to clean it out. I used new gaskets when I put it back together plus some dielectric grease on the connector. It has me completely stumped so for now I put some black tire tape over the check engine light to stop me from going goofy.

Reply to
den630

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.