2005 DGC, 475,000 miles, 3.3L. Custom tuned to 350BHP, bags, flames, limo tint, stretched tires, spinnerz...

Yeah, right. It's a minivan and only the first sentence there is true.

The drivers complaint is that after it cools down, it runs funny for about ten seconds. Don't have much more information from him than that. Scanner shows no codes. Since it only happens cold, I looked at O2 heaters and 1/1 is showing 100% DC and 1/2 is showing 35-45% DC. I have no idea if this is normal or not.

Then I looked at what 1/1 and 1/2 were showing for data and they were mirroring each other exactly. Is that right? I have always been told that if they are mirroring each other, the CAT is bad. That cat is less than 150,000 miles old.

I don't know enough to know if these numbers are normal, or what, so can someone assist this poor dog? I'll even include a rabbit with a pancake on it's head.

 

That is true in most cases about the sensors mirroring each other. But you should have gotten a P0420 code for a bad cat. I would look at the fuel injector harness. We have had some problems with the harness melting at the rear cylinder head.

 

We don't have a P0420, that's the weird part. Any thoughts on the heaters? Is that normal operation? There is also a 2002 DGC here with the 3.3, but I don't know how different things are between them.

 

The custom tune could cause some problems when started for the 10 seconds. I would wait to see if you get any codes and then check that circuit.

 

You know I was joking about the modifications.