Hello again all:

I keep getting a restricted performance situation every 3 weeks or so. It happens under the same conditions each time, which are as follows:

- between 40-45 degrees F (I know sounds strange)
- happens when a longer (15-20 mi) trip is followed by 2 or 3 short in and out stops
- when restarting car after a short stop after the longer trip get a slightly rough idle and then the restricted performance light comes on
- drive for a 3-5 mi light and message goes away car runs fine thereafter
- immediately scan for codes and get the following under pending codes
P0171 too lean bank 1
P0200 random misfire
P1316 Misfire excessive emission fault
P0333 knock sensor 2 circuit high bank 2
only once did the car set hard codes P0333 and P0303 misfire on cylinder three.

I have switched the coil from cylinder three to number one in hopes of getting a bad coil indication. Also, about one year ago I replaced both knock sensors. Checked spark plug on cylinder thre and it was fine.

Any help here would be appreciated - I can't come up with a definitive way to look or repair to make.

Thanks in advance - Blake

 

I would just swap out spark plug on cyl 3 not sure how a plug can be checked, but?
knock sensor could be gone again but would run until codes become fixed.

With I assume P0300 not (P0200) and P0171 you should be seeing fuel trim issues?

Those are the key to your problem? you need live data to find problem.

 

Should have noted car is a 2004 Vanden Plas with 77,000 miles on it.

 

Yes agreed on the checking of fuel trim. Last time it happened I ran live data and found no issues with the fuel trim. also had a mechanic friend go thru the trims with me and he agreed they were in normal ranges. I am wondering if this is some sort of heat soak problem when the car gets shut off and on several times after a full heat up. Again I am reaching but this is definitely annoying. Thanks again.