Need help truck has me stumped

Josh Wilusz · January 24, 2016

I currently own a 02 silverado 2500HD 4x4 with the 6.0 gas engine. Right now my truck will not go above 2000 RPM with driving it down the road. If I manage to get it over that the truck feels like it shifts into neutral and starts miss firing. The first code it threw were the upstream o2 sensors. I changed the driver side and it made it capable of going up to 3000 RPM but no more. I cleared the codes and drove it for a while and then the next set of codes it tripped were the MASS airflow sensor and the front 02 sensors again. There is a 3rd code for the fuel level sensor but that has been on for a while. Any way I cleaned the mass airflow sensor with the special cleaner and did not touch anything inside it. Once I put it back together the truck ran like a dream up until about 15-20 miles and then it went right back to doing the above for 2000 RPM. NO codes at this point drove it to work to try to get a code to pop and nothing until on the way home 4 codes tripped. The truck now wants me to change all 4 o2 sensors. Of course the fuel level sensor is still on as well. At this point I have had it with the codes jumping around and just want to know if someone else has experienced this and if so what did you do to correct it. I was thinking about changing the fuel filter and possibly plugs and wires but I don't know if that would help the problem. I have one guy who says its the fuel pump, camshaft position sensor, Cats, and then the fuel filter. Any advice would be awesome.

Formulabruce · January 24, 2016

May need a new MAF sensor. I had to clean one 3 times to get that truck working well. I have seen these replaced and fix the problem. The different fuel mixtures can cause the o2 sensors to trip and that all starts at the MAF.. good luck@!

justchevytrucks.com may have a good used one you can purchase

davester · January 24, 2016

check fuel pressure at the rail [and that your fuel pressure regulator isn't leaking], both at idle and when you speed up the motor.

check for vacuum leaks

check that all your exhaust bolts are there

Josh Wilusz · January 24, 2016

As far as fuel pressure tests I unfortunately do not have the equipment to do it. At idle the truck is a little lower then what it usually is. All my exhaust bolts are on as I only have 6 which are at the flange coming off the headers. I did have my tail pipe fall off of the flowmaster muffler. That is going to get fixed at tax time with magnaflow exhaust from headers on back. Like I said when I ran that cleaner in the MAF sensor it seemed to have fixed the problem for a little while. My plan of attack is going to be change the MAF sensor, fuel filter, air filter, plugs and wires and then see how it runs. I'll also run fuel injector cleaner through it. I will check the regulator to make sure it isn't leaking. I really appreciate everyone's help with this like I said I was completely stumped.

davester · January 24, 2016

maybe clean the MAF sensor again and/or check that the air filter is clean and properly installed [so crap isn't getting on the MAF sensor].

tbarn · January 24, 2016

Sounds like a cat converter issue. You could take it to a reputable repair facility, rather than blowing $$$$ guessing.

txab · January 24, 2016

check fuel pressure at the rail [and that your fuel pressure regulator isn't leaking], both at idle and when you speed up the motor.

check for vacuum leaks

check that all your exhaust bolts are there

+1

Check fuel pressure for sure. Key on engine off. Part store should have one you can use. Checking cats also

Josh Wilusz · January 25, 2016

All places by me want a minimum of 100 dollars to diagnose the problem. The 100 dollar place is a repair shop that is shady as anything. All the good ones want 300 dollars to diagnose. As you can imagine I do not have 300 dollars which is why I am here as well. My dad is stumped as well. I will check out autozone and see if they have the tools to check the fuel pressure. I can usually figure these things out but when it comes to electrical stuff well let's just say i'm not the best at it. I can wire up a house and troubleshoot house wiring but apparently I cannot do it the right way on a vehicle. I really want to thank you all for your help hopefully I can resolve this before I spend some serious cash that I really don't have.

8Point1 · January 25, 2016

Check that cat.

Josh Wilusz · January 26, 2016

I have a new issue. The transmission when shifting out of 1st gear into 2nd gear has a hard shift. Sounds like the trans is going to be ripped out of the truck. Could it be the transmission is not wanting to shift at all when I put my foot in it?????

Josh Wilusz · April 26, 2016

I never posted what caused all of this here. It was a fuel pump issue. I had the fuel pressure tested and at high RPM it would cut out on me. Changed the pump and now everything is good.