Po141 Po161 Po 304 Po420 . What do i need to do to clear these and will any of these cause the tranny to shift funny? I have to let off the gas to get it to shift and also when it goes into overdrive it seems to drag now. Help Sir expert. :redneck:
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**CRASH** 98 tahoe obd2 codes
- Thread starter Brian H
- Start date
64FJ40
Well-Known Member
0141 and 0161 are from the two downstream O2 sensors.
0304 is a cylinder 4 misfire
0420 is a general code for ineffective catalyst (which matches with the 2 O2 sensor codes)
None of those should matter to the TCU.
History?
0304 is a cylinder 4 misfire
0420 is a general code for ineffective catalyst (which matches with the 2 O2 sensor codes)
None of those should matter to the TCU.
History?
crash2
-Oh no I picked a side-
P0141 and P0161 are for the heater for both post cat O2's. Check the ENG1 fuse to see if its blown. If it is you either have a short or a problem with one of the o2's. I can't see both having the same heater problem
P0304 as eric said is a miss fire on cylinder #4
P0420 is a 3 way catalyst code for your bank 1 catalytic converter. You need to get the heater issue resolved to verify the catalyst operation but I am pretty sure its a bad cat. A missfire will kill a cataytic converter but whats odd is the catalyst code is for the other bank than the miss.
None of these will cause any shift issues that your having and in 98' its a VCM and all trans control is in the VCM (not a seperate module)
Hope this helps
P0304 as eric said is a miss fire on cylinder #4
P0420 is a 3 way catalyst code for your bank 1 catalytic converter. You need to get the heater issue resolved to verify the catalyst operation but I am pretty sure its a bad cat. A missfire will kill a cataytic converter but whats odd is the catalyst code is for the other bank than the miss.
None of these will cause any shift issues that your having and in 98' its a VCM and all trans control is in the VCM (not a seperate module)
Hope this helps
TreeClimber
Well-Known Member
More than likely it's the opposite. A bad O2 will send too much fuel thru the engine, causing unburnt fuel to exhaust. That fuel will 'burn' during it's trip thru the catalyst convertor, causing the 'cat' to melt internally, which clogs it.
A 4th cyl miss will also send too much fuel into the exhaust.
Either way, you need to fix all three.
Although some backyard mechanics have been known to 'clear' a clogged cat.
crash2
-Oh no I picked a side-
No---the codes you have are direct reference to the heater circuit within the O2.
And removing and clearing an O2 you will get a P0420. It takes the pre and post O2's and calculates if the converter is working or not. I can sit there and watch the post O2 and myself know if a cat is bad or not.
skinny_pedal
Well-Known Member
Got a leak down tester....you may not be getting any boom out of that cylinder. Bad valve or cam are pretty common to my knowledge
crash2
-Oh no I picked a side-
Or carbon building up around the valve---that was common...
deerlick
Well-Known Member
i would guess you have a valve problem on #4 if the other parts didnt cure your misfire. that mis could have helped contribute to your failing cat as it would have sent unburned fuel into overfueling it and overheating it melting the catylst inside. the tranny may be feeling as its shifting odd from a cat that is coming apart and plugging up, sometimes the pieces of cat will get stuck in the outlet and plug up the exhaust then fall back down and feel normal til it does it again. so leak down on that cylinder would be the next step for sure. also clean the mass air flow sensor as they are very known for killing trannys in those if they are dirty and skewing the readings on it.
crash2
-Oh no I picked a side-
Basics--always start with the basics. Verify it has compression. Like Gavin said also do a leak down test if you have a compression problem. Also they are known for breaking valve springs.
