Can anyone help me diag my 6.0

[Willyjr]

I've replaced the tps mass air flow all 3 of my o2 sensors and it's still telling me I have a misfire and it's giving me the same codes for my o2s again I bought this truck less than 2 months ago with 120000 miles and have put over a grand into it can anyone give me any suggestions on what my next route should be I don't have all kinds of money to continue to chase the maybe maybe nots thank y'all alot

[Formulabruce]

Hi Will, what an introduction!. Grab a can of Mass airflow sensor cleaner, AND Throttle body cleaner, ( 2 Different cleaners) take off the big air inlet and clean it all spotless, including the throttle plate ( cost UNDER 15 bucks) .. Good luck, and welcome to the Forums....

[dewfpo]

Is your misfire code on random cylinders or one consistently?

 

DEWFPO

[Willyjr]

Thank you

[Willyjr]

My misfire is random, I went ahead and threw me intake manifold gaskets on it still no improvement all the forums I've read are telling me knock sensors but it keeps throwing o2 sensor codes I just replace those last weekend and random misfire p300 code

[dewfpo]

Do you know if the spark plugs were changed at 100K miles? Have you run an good fuel system cleaner like Techron or similar thru the fuel tank?

 

DEWFPO

[txab]

What are the exact O2 codes?

 

May need a crank re-learn. Sometimes can be the issue.

 

But plugs, wires, MAF etc... to be checked thoroughly first

[SILVER SLED]

Take it to someone who can relearn the crank position sensor. Shouldn't cost more than an hour of labor at any given dealership.

[davester]

exhaust leaks will also throw off the o2 sensors. and the 6.0l motor is known to break exhaust manifold bolts. see if any manifold bolts have broken off.

[Willyjr]

Right on y'all I appreciate it like I've got new plugs intake gaskets o2s maf tps and my codes were p131 137 151 157 and 300 I had to look them up but an exhaust leak would make sense for it throwing the o2 codes still

[carkhz316]

What are the exact O2 codes?

 

May need a crank re-learn. Sometimes can be the issue.

 

But plugs, wires, MAF etc... to be checked thoroughly first

 

 

Take it to someone who can relearn the crank position sensor. Shouldn't cost more than an hour of labor at any given dealership.

Yes so much to the crank relearn. I've been seeing the p0300 being solved by a relearn more and more. IIRC, there is even a bulletin about doing a crank angle relearn practically any time a major service is performed, including after tuning. Case in point: My '03 2500 6.0. I played around with it with HP tuners. Since most of my driving is unladen, or city driving, I didn't notice it for about 6 months. It wasn't until I took a road trip with a car trailer, when under load doing 70mph+, it would suddenly start flashing the CEL, and elicit a P0300 code. TC would unlock for about 10 minutes each time. Mind you, despite a flashing CEL (Class A, catalyst damaging misfire) the truck would run perfect; i.e. it wasn't actually misfiring. After a few tests, I finally performed a crank angle relearn via HP tuners, and it cured it.

 

Regarding your O2 codes, it's unlikely that all 4 have crapped out at the same time. You either have a massive exhaust leak, or their is a wiring issue (damaged/ cut/ pinched wires) causing the low voltage on all 4. I'd start with a visual inspection of the wiring.

[nekkidhillbilly]

clogged cats could do this. 6.0s are bad to.

[Willyjr]

Thanks alot guys I have a direction to go this weekend I'm gonna go through a d check all the wiring I've basically got all new sensors it did read a maf circuit code the other day and the wiring and exhaust are the only thing left

 

 

Yes so much to the crank relearn. I've been seeing the p0300 being solved by a relearn more and more. IIRC, there is even a bulletin about doing a crank angle relearn practically any time a major service is performed, including after tuning. Case in point: My '03 2500 6.0. I played around with it with HP tuners. Since most of my driving is unladen, or city driving, I didn't notice it for about 6 months. It wasn't until I took a road trip with a car trailer, when under load doing 70mph+, it would suddenly start flashing the CEL, and elicit a P0300 code. TC would unlock for about 10 minutes each time. Mind you, despite a flashing CEL (Class A, catalyst damaging misfire) the truck would run perfect; i.e. it wasn't actually misfiring. After a few tests, I finally performed a crank angle relearn via HP tuners, and it cured it.

 

Regarding your O2 codes, it's unlikely that all 4 have crapped out at the same time. You either have a massive exhaust leak, or their is a wiring issue (damaged/ cut/ pinched wires) causing the low voltage on all 4. I'd start with a visual inspection of the wiring.

[jaysons]

Is it actually missfiring? .... As in, is it drivable, or is it missfiring so bad that its unsafe to attempt driving it?

[jaysons]

I have an '01 6.0L. and it worked fine... shut it off, and started it 4 hours later, and it took half throttle to start it and had to keep it there or higher to keep it running. Then, eventually, the dreaded "Po300" lit up. Took a while of troubleshootin, as it was giving codes for o2 sensors, maf, knock sensors, lean on banks 1&2, amd a bunch more, just randomly.

 

Turned out to be a broken valve spring on #4 cyl. Ex valve. Top of spring broke and twisted itself down into the rest of the spring, so it wasnt making any rattling or noise at all.

 

Moral of my story : do a compression test on ALL cylinders.