Need help with code p1135

It was the upstream sensor. Replaced with denso sensor and no more CEL. No rust on mine. Southern truck with only 100k.

 

After a week of trouble shooting a loose ground wire was my issue

 

You will never forget this for the rest of your life and when you work on your buddys truck that has a problem and you figure it out you will be the hero, unpaid, but a hero.

 

A bit late to this thread but I'm having the same issue. Do you know where exactly the ground wire is located on upper intake manifold? I've searched everywhere and can't seem to find it

 

On the 3.4 locate the DIAGNOSE plug on the D/S upper intake, look by it and you will see a bundle or brown wires with black tracer. Take the bundeled ring terminal connections off the stud and give each individual wire a little tug and bend right where they are crimped. Lots of times the wire is broken internally.

 

Thanks! I'll give it a try later. Really hoping this is my dilemma as the sensor in question is a brand new DENSO. Not sure what else the issue could be...

 

Check for an exhaust leak.

 

Funny you mention this! I do, in fact have a pretty big exhaust leak (muffler is filled with rust cracks on edges). It's a bit loud and you can definitely smell it. I have a new one ordered and will be installing it this upcoming week. Hopefully that remedies the code.