EGR Valve Cleaning

[rdnkcpa]

My son has a 2001 S10 with a 4.3L with 175,000 miles, and has a PO300 random misfire code. I did a little poking around on the net and it has been suggested that the EGR may be plugged up and cleaning it may help things. Is this possible and if so would it help? He seems to get the CEL when the A/C is on and the engine is under acceleration/load. Cap & rotor are new, less than 10K miles, and the plugs and wires have ~40K on them.

 

Before I start taking things apart I thought I would ask and see if this would be helpful.

 

Thanks in advance.

[Jsdirt]

That code is my nemesis ... I parted out a '00 Jimmy after dealing with that. Was the final straw in a large hay pile of them ....

 

First thing to check on those is fuel pressure - it's quick and easy. Anything less than 55 lbs. and it won't run right. The next issue with those is the intake gaskets leaking. Spray carb or brake cleaner around the manifold gaskets and note any changes in idle speed. That would indicate a leak. The other common problem is that miserably stupid wonder of engineering known as the spider - they all fail at some point by leaking fuel all over the place. If you run out of options, pull the upper intake and check for a puddle of fuel in the lower intake. If so, you probably need a new injector or 3 .. but might as well just replace that whole stupid spider assembly.

[burnettw]

If you pull the upper intake, look to see if the top of the intake manifold (where the spider sits) has a really clean area as compared to the rest of the surface. If so, that probably indicates a leaking pressure regulator where leaking gas has washed the surface clean. Considering the age of your vehicle, I would replace the spider assembly. Good prices at Amazon and Rockauto.