Wayne Smith

2010 C4S PDK, still all original running gear ...

Leg one yesterday. It looks like the old girl still can push out some mpgs, even at speed.

But a CEL near mile 400 indicates I may be coming due for cats or O2 sensors (P0431). I'll try running some cleaner after I get home. Any recommendations?

TRINITONY

cataclean.

Wayne Smith

Thanks. My son suggested that same brand as well. I was at his house in the midst of this trip. It will be delivered on Wednesday.

Meanwhile, I drove another 600+ miles after we cleared the CEL with no reoccurrence.

I've got another 6 or 7 hundred miles to drive this week so I'll put the CatClean in after that just for good measure.

TRINITONY

remember your tank has to be below a 1/4 followed by an Italian tuneup for it to work

Wayne Smith

Thanks 😊

Bruce In Philly

2009 C2S 202K miles

Interesting that such a neurotic group and we here have not addressed catalytic converter health.

What about the LiquiMoly product that you spray into the intake? This is not to be added to fuel. Any input?

https://www.liqui-moly.com/en/cataly...cription-title

Peace
Bruce in Philly (now Atlanta)

Wayne Smith

The 5 North was so bumpy last night that the driver's side map light broke at all four solder joints. The LED bulb was rattling around in its chamber. Once I soldered it back together, all was OK.

Hmmm ... What else took a hit and is preparing to fail. Now I'm beginning to sound like Bruce!!!!

Note: On a drive across the Sierra a couple of weeks ago, my TPC DSC defaulted to full stiff, so the car had 600 miles of bumpy ride that day as well. I swapped it for the original controller, and all was fine. A couple of days later, I put the TPC unit back in, and all was good as well. The old adage ... There's no such thing as a good connection (some are better than others, but none are good). Then again, sometimes electronics just need to be powered down for a while.

The suspension was working fine last night. But the road was quite sub-par. These cars do put up with a lot of abuse!!!!

For the record ... We hit 160K miles in Laguna Beach. And then drove almost 500 miles further. We got home at 2:30 this morning.

Still no oil burned

JGEMDOC

lol i get like 1/2 that normally. at best on a 1600 mile road trip i was getting 22ish, but also hammering it at 95-110 for most the highway driving.

Wayne Smith

Passed 161K miles yesterday.

No return of the CEL. So, to CatClean or not to CatClean? That is the question ...

At above 100 mph my mpgs drop to the low 20s as well, or so I've been told!!!!

Busta Rib

According to my tech, there are other variables that go into the P0431 code, which is a generic Cat code. Do you have the stock exhaust or any aftermarket components? There are also pre and post-cat O2 sensors. If you have the right diagnostic tool, you can hone in on which bank is throwing the code and start troubleshooting by swapping the pre and post cat sensors and see what happens. Finally, it can be as simple as a loose O2 sensor or bad wiring. For realz. Good luck finding your problem and solutions.

Wayne Smith

You've made good points. If the codes come back the Foxwell will come out.

I've got the Fister (gundo) mufflers. No other revisions. That's well behind the cats and the O2 sensors.

As my father in law was fond of saying ... There's no such thing as a good connection. Some are better than others, but none are good. Even actual failures beyond connections often can be traced back to connection problems. This mantra works beyond electrical to mechanical and hydraulic as well.

I had filled with a different brand of gas a hundred miles before the code popped up. That was the only variable. I've got 1500 miles since then with no indications of a problem. Fingers crossed.