I have a 2004 Chevy Suburban 5.3L AWD with about 170,000 miles on it. Having several issues. Previous owner deleted oxygen sensors. It has run good for about 30,000 miles( as long as we have owned it). Sometimes idles rough. After it has run a while and I try to restart it it just cranks till I turn the key off and try again. Sometimes it will stumble and die during this process and the start. Lately has started kicking out of gear and engine races, then slams back into gear. It does this several times. I changed the maf and air box because it was broken and flopping around. This seemed to help for about 60 miles, but then started again. the codes that I am getting are: PO 101, 171, 174, 342, 442, 446. Thanks in advance for any help.

 

Welcome to Chevy - I have seen kicking out of gear caused by a broken engine mount

 

Thank you for the reply. I will check the mounts. I live on a very rough dirt road.

 

The mounts may look fine; I figured mine out revving the motor and could see it lifting up too much. A jack under the moter could show it as well

 

For starters I would clear all the codes, and start fresh, see which codes come back, your lean codes could be attributed to your Evap leak, will have to do some diagnosis, you do have a Crankshaft communication code, this could be causing your run condition, easy way to tell is when it cranks but doesn’t start watch your RPM gauge and see if it is responding, or connect a scantool if you have access to one, and read RPM data, if no response, the PCM is not receiving a signal from the Crankshaft sensor, i just had this issue on my 04, after checking sensor wiring and Reluctor wheel, i replaced the sensor with ACDELCO factory sensor, they are pricey but necessary, after replacing the sensor it may need to be learned, mine didn’t, i even tried to learn it with my scantool, it wouldn’t learn but runs amazing, think it was just happy to see a good signal lol

 

Checked mounts. They are tight. Thank you for your post.

 

Thanks Hulk40187, I will clear the codes and see where I am at.