Codes P0420 AND P0430

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Feb 10, 2016 | 05:56 PM

#11

BlackLX4

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Quote:

Originally Posted by PAhonda

You really should verify the upstream air/fuel sensor is responding to the engine exhaust and see what kind of fuel trims you have.

I'd hate to suggest spending money on a new converter and not have it solve the problem.

PAhonda, I just checked the fuel trims and the short term trim was bouncing between -5 and -10, but it mostly stayed in the -5 to -6 range. Long term trim remained steady at -1.6. Both are lower than they should be according to the service manual - the short term trim considerably more so. Manual states 1.0 +- 0.2 for the 2.3L. How do I go about finding the cause?

Quote:

Originally Posted by poorman212

If you are outside of the country of CA there are plenty of places you can find a replacement cat for decent prices (rock auto, local parts store with discount codes, ect). "IF" you go down that road, go ahead and get new O2's (up and down stream) and replace those as well, if they are more than ~a year old. Then look online for a "used cat buyer" - the metals used in them will get you some money back.....say $50 to $100.

I will definitely look into that!

Feb 18, 2016 | 11:22 AM

#12

BlackLX4

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Bump. The fuel trim levels are telling me that the engine is running too rich. Should I look for a potentially bad fuel pressure regulator?

Feb 18, 2016 | 12:14 PM

#13

JimBlake

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From: Wisconsin

The quick test for a ruptured FPR is to look for liquid fuel in the vacuum hose. There should not be any fuel getting into that hose. (But that doesn't rule out some more subtle problem with your FPR).

A proper test of the FPR is to measure fuel pressure while the engine is running.

Feb 18, 2016 | 12:55 PM

#14

BlackLX4

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Quote:

Originally Posted by JimBlake

Don't you need a special gauge and adapter to test the fuel pressure, or can it be done with a regular fuel pressure tester?

Feb 18, 2016 | 04:00 PM

#15

JimBlake

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From: Wisconsin

I don't think the gauge is special. Just the fittings to connect up to that funny arrangement of fittings on the firewall. That's where the fuel supply pipe comes up from the fuel pump & connects a rubber hose over to the FPR.