Hello all, I have been getting this engine code for about a week now but the truck has run perfect until today. Now today it will barely idle and is now showing the following pending codes.

P0171 Too lean bank 1
P0174 too lean bank 2
P0300 Random/multiple cylinder misfire detected.

A quick google search tells me it could be many things. Can anyone advise me where to start?

I have a 2006 Escalade Supercharged, custom tune, headers, cold air intake.

Please help I'm not sure where to begin. Thanks!

 

Sounds like you have some sort of massive vacuum leak to give you lean codes on both banks aswell as make it really hard for the truck to even idle and toss misfire codes.

 

This sounds crazy but I had the same codes after a header install. Everyone said it was vacuum leak when we put it on the computer and one of my o2 sensors was out. I never did get a 02 sensor code hope this helps, I put a new one on been perfect ever since.

 

Interesting. It was too lean bank 2 for a while and ran fine. I'm nervous it is the intake. Im just not sure how to troubleshoot things like O2 sensors and such.

I have an pretty advanced engine code reader that does real time Analysis while truck is running but im not sure what to look for.

 

I've read online that it could also be the intake gaskets leaking or the bolts on the intake manifold were loose. I had the same thing when I bought my truck. I cleared the codes and then it had a P0000 code. I tightened tried to tighten the bolts and they seemed tight but the CEL went away right after. Hope this might help. Can't hurt. Just make sure you torque the bolts per specs and sequence.

 

It's my lucky day! On the back of the magnacharger there is 2 vacuum lines. One is just capped, the capped hose was rotten and leaking huge vacuum. Plugged it off and we're good to go. Hope this may help someone in the future. Thanks for all the help!

 

I'm going to say 02 sensors and possible cat plug if your still running them