I replaced the LIM and UIM have driven the car for a few days ( about 150 miles ) with no apparent problems . ( see http://www.bonnevilleclub.com/forum/...=asc&start=20_) However, the check engine light came on today . I stopped by Autozone and had them read the trouble code . The code was P0401 - "The PCM has determined that there is insufficient flow in the exhaust gas recirculation system " . I immediately thought of a misaligned "stove pipe" in the new Dorman UIM but I was extremely careful in tapping it down flush with the surface of the UIM and making sure it was running perpendicular . What is the best way to troubleshoot this problem. Is it ok do drive the car like this for a week if need to R&R the UIM ? - Thanks

Please edit your profile to add a signature to your posts that includes the year and trim level of your car. That will help us to help you more easily.

No one has yet reported a problem with reduced diameter stovepipes restricting flow in the EGR system. More likely, the EGR valve is plugged up and needs a good cleaning. Another thing that can happen after LIM work is the corrugated stainless tube carrying exhaust gas from the EGR to the LIM can crack and leak, but it doesn't seem like that should cause a restricted flow code to set. :? Was the EGR passage in the LIM clear before you drove in the new stovepipe?

I was thinking about cleaning EGR cleaning and checking the tube to the UIM first. I guess that might be the most logical step in determining the problem . Those 2 bolts look pretty rusty and I am concerned about the risk of them breaking ( does it often happen ?) . Got a link to the EGR cleaning procedure here ?

I did not notice any restriction in LIM when I installed the stovepipe in the LIM .

Is it OK to drive the car like this for a while ?

Any other suggestions or recommendations are appreciated .

- Thanks

Use some PB penetrating oil or Sea-foam deep creep to loosen the rust. Use the search feature at the top of the page to learn about cleaning the EGR valve, pintle and passages. It is not rocket science, but it is an expensive part.

You aren't kidding . The valve is like $ 155-175 from the chain auto parts stores. I hope that those rust breaking penetrants work as they are hyped up to be ( basically just a combination of solverts and reatly don't understant how they can dissolve rust.)