As I said, I just passed smog so I have about two years to really worry about this. But my 25mph NO reading was 458, with 498 allowed. I got 233 at 15mph, which is right at the average reading. HC was kinda high at 15mph, at 45 (allowed is 59). Basically, the NO values are both up from two years ago, and the HC readings are up a bit. Since HC and NO are both up from last year, seems to me that something is failing. Just checked for codes, and got the following:
KOEO - 111 PASS, Memory Codes: 212 and 334
KOER - code 116
(Pulled code values from http://www.troublecodes.net/ford/)
If I remember right, 212 indicates a PIP problem, and 334 says "EVP sensor is/was high – EVR". Not sure what that means, except that the EVP sensor is attached to the EGR. I've suspected the plastic vacuum lines were cracked and letting in un-metered air, but never got around to test it. I didn't let the engine warm up for KOER, so 116 (ECT out of range) was expected.
The EGR was replaced 2 1/2 years ago with a Motorcraft unit. My cats are new - I have a Bassani x-pipe with the high-flow cats, and I added two more high-flow cats (a total of 4) to pass smog two years ago.
Some internet research indicates that high NO on a Mustang 5.0 usually indicates the engine is running lean. If I'm getting bad values out of the EGR that could be the reason. I have no idea how to test the EGR system nor if it's really a vacuum issue.
If the PIP is failing, that would explain the small bit of stumbling I get. It only happens when I'm maintaining speed, then step on the gas. If I'm light on the gas pedal (not too often), the stumbling is barely noticeable. The stumble only lasts for a couple of seconds, then it goes away and the engine is back to normal. The engine also seems to run just a bit rough when it's cold, but after a couple of minutes of driving it's back to normal.
Any ideas would be appreciated.
KOEO - 111 PASS, Memory Codes: 212 and 334
KOER - code 116
(Pulled code values from http://www.troublecodes.net/ford/)
If I remember right, 212 indicates a PIP problem, and 334 says "EVP sensor is/was high – EVR". Not sure what that means, except that the EVP sensor is attached to the EGR. I've suspected the plastic vacuum lines were cracked and letting in un-metered air, but never got around to test it. I didn't let the engine warm up for KOER, so 116 (ECT out of range) was expected.
The EGR was replaced 2 1/2 years ago with a Motorcraft unit. My cats are new - I have a Bassani x-pipe with the high-flow cats, and I added two more high-flow cats (a total of 4) to pass smog two years ago.
Some internet research indicates that high NO on a Mustang 5.0 usually indicates the engine is running lean. If I'm getting bad values out of the EGR that could be the reason. I have no idea how to test the EGR system nor if it's really a vacuum issue.
If the PIP is failing, that would explain the small bit of stumbling I get. It only happens when I'm maintaining speed, then step on the gas. If I'm light on the gas pedal (not too often), the stumbling is barely noticeable. The stumble only lasts for a couple of seconds, then it goes away and the engine is back to normal. The engine also seems to run just a bit rough when it's cold, but after a couple of minutes of driving it's back to normal.
Any ideas would be appreciated.