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Followup To
Question - You talk about a "coil" what coil do you mean? Also a converter for $100.00 do you mean the cat. converter? What is the warranty on the cat. converter for an 01 Frontier. The downstream and upstream sensors were changed 20,000 miles ago . Thanks, Have a nice New Year, Rich
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Followup To
Question - I took the plugs out, they're all clean, no fouling at all. I also checked the resistance at all the injector connectors and get a reading between 9.6 and 9.9 ohms, book calls for 10 to 14, seems close enough to me. How do I check the pressure regulator? Or should I just change it.
I've written you about this problem before,I have a 2001 Frontier 4cyl 2WD 126,000 highway miles. The check engine light is on again I'm getting a P0420 reading "catalyst system malfunction,right bank."Does'nt right bank mean you have a V6 or V8? Per your suggestion I put the injector cleaner in the gas a few times, light stayed out for 1000 miles, I have not run a test on the injectors yet, I have noticed when I pull into my garage, shut it off and get out I'm getting the rotten egg smell, could it be the converter, and is there any test I can run to check it out? Possibly a vacuum test? Before I forget, I changed the oxygen sensors at about 105000 miles. Thanks, Rich
Answer -
Rich,
Either you have a defective fuel pressure regulator or you have a stuck injector. The code means that the engine is running rich and the rotten egg smell pretty much confirms that there is a fuel management problem. I would say that I would check injectors first as well as fuel pressure to make sure that you do not have a stuck injector or bad pressure regulator. Remove the plugs and examine them to see if one or more is/are blacker than the others. If one or more is really black then that is the hole with the stuck injector.
Answer -
Rich,
Either you are getting too much gas like a stuck injector or you are not burning it. So, if the injectors are working properly I would be looking at a coil. The P0420 means that the coonverter cannot get the smog under control and that could mean that you are burning oil and the converter has finally given up. A hundred dollars for a replacement converter could do the trick. The sensor it talks about is the back one as there is one in front of the converter and one behind. Yes, they were lazy when they came up with the code but it means the back one. If all checks out good up front I would change the converter.
AnswerRich,
You have four coils that fire the plugs. Usually, if one is bad you will get an error code to the corrisponding coil and you do not. Or you will get a multiple cylinder misfire. You say that the sensors were replaced so I think the converter might be defective since you say the plugs look good and the injectors are close on the ohms check. I still think the fuel pressure needs to be checked to make sure you are getting the proper amount of fuel. But, if the fuel pressure checks good then the converter must be bad.
