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Flashing check engine light comes with excessive misfires, that's a standard thing.
My internet expert diagnosis is that the catalytic converter on that bank is choked up or collapsed.
But i've had a few cars with choked cats which caused misfires like this, so it's not a guess, it's speaking from experience.
I would suggest a proper diag tool such as the IID would shed more light however Cambo above sounds like he’s on the money.
I'd love to do this, but don't have one. Is there an Adelaide member that might loan/rent one prior to me finding one to purchase?Quote:
Originally Posted by DiscoJeffster
I do like this idea, as in the absence of a manifold pressure/flow/EGR/HO2S/injector fault code then back pressure may be causing this. Also the sudden failure on a whole bank after a long drive supports this.Quote:
Originally Posted by Cambo@oldjaguar
Given that it runs fine would I be safe driving this car?
I guess putting a pressure gauge on the upstream HO2S (O2 sensor) port might yield a high pressure if this was the error. Does anyone know if such a tool is available?
You can measure the pressure in each pipe and compare the differential pressure before and after the cat. The problem is that a collapsed or choked cat may flow enough gas at idle, but not at higher rpm under load, so how do you test under the right conditions?
In saying that, the last car I had with a collapsed cat you could actually feel the reduced flow just by putting your hand over each tailpipe with it sitting there idling.
If it is a cat issue reading the codes will show this.
If no IID tool is at hand the car needs to get to an indy or even a stealer and have them read.
Garry
The site has a list of owners of diagnostic tools. Here's a link showing Adelaide members.Quote:
Originally Posted by Julian B
Members with Diagnostic Tools
Martin
What's the code for a collapsed or choked catalyst?Quote:
Originally Posted by garrycol
I had a look at my PDF workshop manual.
This is a cut and paste of the P0301 code. It refers to cylinder 1. The others refer to other cylinders - P0302 to 2, P0303 to 3 etc. P0300 says "Random Misfire Detected -No sub type information"
Attachment 135112
Martin
Astute observation re conditions for testing, which I will reflect on.Quote:
Originally Posted by Cambo@oldjaguar
Local independent can't see it for a month.Quote:
Originally Posted by garrycol
So I just used the OBDII interface on the cheap reader I have.
Interrogating the STFT (short term fuel trim) it appears to read -25% on bank 1. Coupled with misfires all on that side I would hazard a guess that the computer is compensating by enriching the mix on that bank for all cylinders, so the next question is why is this occurring?
To me the logical extension is a vacuum leak on that side, and from reading extensively it sounds like the likely culprit is the manifold gasket, though a sudden leak there seems unlikely unless the computer has been compensating for ages on a slow leak and only now shows a misfire. Alternatively one of the vacuum hoses has broken or come off, but this would need to be on the misfiring side only.
Curious though is the lack of error code saying too rich on that bank.
The only other culprit could be a faulty upstream O2 sensor sensing constant lean condition and ordering enrichment to compensate. I have a spare downstream O2 sensor as I bought a pair to replace the other side with a heater fault, but just didn't have time to replace a functioing part.
What do people think?