c3nthusiast

So the dealer told me I had bad CATS. I noticed that after putting Techron Fuel cleaner it would go away after the tank was done. It happened 3 or 4 times. Turns out it wasn't the Techron that made it turn off. It was Wawa gas. What is so different about their gas? Am I crazy?

Plutoe

You are crazy---in Amerika all grades of gas are refined to the same spec---then some whaoos add specific combustion cleaning additives----there are no real cat cleaning additives.---therefore you must like the donut girl a wawa's

IGB

Did they tell you which particular OBD-II codes it was giving?

I've had P0420 & P0430 codes a couple of times (whch are defined as "Catalyst System Efficiency Below Threshold (Bank 1)" & "Catalyst System Efficiency Below Threshold (Bank 2)"...

As for gasoline, I have not attributed it to one brand of gasoline as of yet, mostly, I use Costco gas which is rated as a "Top Tier" gas and they claim "contains five times the EPA detergent requirement"...

Which basically has the same effect as Chevron Techron, but may be I will try out a bottle of that stuff to see if it makes a difference.

IGB

I don't think anyone has suggested that there are "cat cleaning additives". But if you're burning dirty gasoline, then the ratio of gaseous material that is passing are being tested by the pre-cat O2 sensor versus that which is measured by the post car O2 sensor will be completely different than if you were to be burning cleaner gasoline.

So while additive might not clean the catalytic converter, they do impact the readings that will trigger the check engine light if they are out of balance.

That said, there are other causes that can trigger the same code I posted above:

- Three way catalyst converter Bank 1
- Exhaust tube
- Intake air leaks
- Fuel injectors may be faulty
- Fuel injector leaks
- Spark plugs may be faulty
- Improper ignition timing
- Engine Control Module (ECM)

Which really, makes this quite the headache to try and diagnose!