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EVAP leak and low catalyst efficiency


Topic starter

I have a 2008 GMC Envoy Denali with a 5.3 V8 and I have these three codes and I was wondering if I don't do anything about this will it ruin my engine or make the engine loose power.





2 Answers

well first you need to know to the exact code definitions. Look them up on

If you're still unsure, then post the full fault here and we can help you out.

Already know I got the fixd app I just didn't know how to send a screenshot on here

screenshot instructions are posted on the front page. Upload them to an image sharing site and post the link.

Common troubles codes can also be found in our FAQ.

thanks. if you use the download link, then the image will be displayed. I've edited your top post.


The EVAP leak you should fix. It could make your car run like crap.

You can search Scotty's youtube channel he has videos about it. Might be as simple as a gas cap.


The others mean your cats are probably going out. You can read more about that in our FAQ.