Questions & Answers for: cel p0420

...P0420 code include: Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required.Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the ...

P0420 code will not clear. I replaced the rear O2 sensor and the CEL is still on. I used the scan tool to clear the code but it will not clear. that code is saying you have a problem with that system.

CEL to light, clearing the code just clears the code, turns the light off. , if the problem is still there, the light will light up again. I cleared my P0420 for a bad cat a dozen times before I fixed

...CEL codes is available on the internet. FYI the most common code for contour's are P0420 and P0421. These won't cause any driveability issues. As for your heater problem, your fan blower relay is ...

...CEL comes on and you have a P0420. Before replacing the cat, clear the code and see if it comes back-if it does, you might try first replacing the O2 sensor. If that doesn't work, get a 'oil fouler' ...

...cel code p0420 it will as long as you don't have a cat on the system, there are after market parts that will give you the part to trick the reader to see a cat, so you need to ask if you have changed ...

...P0420 Usually indicates a bad catalytic converter or a bad oxygen sensor. Since you car is 2008 my money is on the oxygen sensor. Or it could be something as simple as an exhaust leak. The cruise ...

...p0420 The first thing I advise on this kind of situation is DO NOT just randomly throw money at it. I would never repair a P420 or P430 without turning the CEL off several times and making sure I got ...

...CEL displayed code P0420 & 1150 what could be the problem Mine is a 2001 Sienna LE. I got the P0420 code and the dealer want to replace an engine control computer for $1600. I've found posts that ...

p0420 2003 pontiav grand prix CEL on and the guy at the auto shop says its a code p0240 whats that Mean? what might the problem be? and solutions? So which code is it .