P0305 - 2000 tahoe z71 gmt400 4L60E

[hwhwhw]

2000 tahoe z71 gmt400 4L60E

P0305 Cylinder 5 Misfire Detected Confirmed

P0300 Random - Multiple Misfire Detected

P0141 Oxygen Sensor Heater, Circuit Bank 1, Sensor 2, Intermittent

 

[SunlitComet]

you cant poll this there are to many variables in a misfire situation. you have to remove plug wire and dizzy cap to find out why it is not firing. if you find nothing you may need to compression test and/or injector balance test as well to find out why the misfire is occurring.
as for the o2' solve the misfire first or your going to have bigger problems the just an unrelated o2 issue.

 

[Monstar_est87]

X2... O2 issues could be due 2 the misfire... just hope u have better luck then me... Got bad O2 readings then misfire... Spark plug was busted, so it was replaced along with new cap, rotor and plug wire... Still misfiring... THEN... Cracked head... Cylinder 6 was misfiring due to the cracked head not holding compression...

The 2000 Z71 (4X4) LIMITED is The 2000 TAHOE LIMITEDS (2WD) big sister... As us LIMITED owners know nothing can ever happen 2 these unicorns... But I strongly believe this is what the Mayans were taking about when they mentioned Dec 21 2012...

 

[retorq]

Just think, if your wrenching skills were on par with your internet forum poll making skills you would have a truck running on all 8 cylinders. I voted head gaskets.

 

[hwhwhw]

spark plugs replaced, spark wires replaced, distributor cap checked and cleaned

compression test passed on all cylinders (sorry not the headgasket @retorq, wanna guess again?)

still getting a misfire on cylinder 5 every 50-60rpm

taking apart the manifold next to get at the fuel injectors...

---------- Post added at 11:14 AM ---------- Previous post was at 11:13 AM ----------

anything can be polled. this is the internet!

 

[hwhwhw]

ok so it turned out that two of the valves were burnt out and stuck, on cylinder 5 and cylinder 7

had to have the headers pulled off and sent to a machine shop

everything is polished and cleaned and replaced now

engine is now cleaned out too

and high temp brake fluid while they were at it

total was $1400 for rebuilt headers, all new gaskets and hoses, new spark plugs and wires, cleaned distributor cap, replaced all fuel injectors, oil change filter, coolant flush and refill, brake fluid.


runs better than ever

 

[hwhwhw]

Rained a bit the last two weeks and started to get misfires; local shop found a crack in the distributor cap. Replaced for $200 and running great now. After it was fixed, I cleared the MIL because I figured the O2 sensors were pissed from the misfires, but they keep coming back...

Latest ODB2 scan results here for your amusement:

P0102 - Mass or Volume Air Flow A Circuit Low Input - History MIL

P0102 - Mass or Volume Air Flow A Circuit Low Input - CONFIRMED



Any suggestions? I heard maybe the sensor just got dirty when the engine was misfiring with soot. But my understanding is this is on the INTAKE side of the engine? I also heard to check for corrosion on battery terminals? What's the deal

 

[SunlitComet]

Yes it is the intake side try cleaning the senso first. It can get contaminated from the air that runs thru it. Not sure why battery cables were brought up.

 

[hwhwhw]

for the record, cleaned mass air flow sensor months ago, cleared codes, never came back, runs great