TX Z06 02

Long story short, I filled up with gas the other day and 10 miles later I get CEL P0133 and P0153. All signs point to contaminated gas.

To be on the safe side, I want to drain the tank completely. I have done searches on this forum and see where people recommend using the fuel pump and draining from the fuel rail, but that still leaves a few gallons in the tank. If its contaminated with water, have i really removed the contamination since it will be in the bottom of the tank?

Any other recommendations?

Jud Chapin

I personally doubt it's the gas. I see stories about it on various forums and all I know is that I've been driving for over 50 years in all parts of the country and have never had bad gas. That's not to say I never thought it was a possibility when a driveability issue arose, its just that the problem always turned out to be something else.

TX Z06 02

Well, I thought i had done a thorough research and came up with a few threads from this forum that said causes are typically:

Exhaust leak - i have no leaks
Bad 02 sensors - i find it suspect that both 02 sensors failed at the same time
Contaminated fuel - i find it weird that it ran like a raped ape up until the time I refueled, drove 10 miles and it starting running considerably worse, and then the CEL

This thread was very detailed and it didnt mention LT headers as the cause.

I havent came across any threads where just the LT headers cause the problem. I will continue to look, but I have ran the LT headers for 3 months now with not one single issue? Wouldn't that issue be almost immediate?

The only thing I have done recently is a mail order tune from ECS. Would that have triggered the 02 issues/CEL?

CQRT

If indeed it was bad gas, then you won't be the only one with problems. Suggest you go back to the station and inquire before going through the steps to drain the gas.

If it was a problem, the station should pay/reimburse your repairs.

TX Z06 02

I did go back to the station and file an incident report. Their Risk Management people called me back and said after a brief investigation, there were no other claims and they have had no issues with water. I have a claim number, but that's about it. i just wanted to have it on record in the event something else happens.

So here is the timeline for mods:
Mail order tune ~ Jan 25th, 150 miles ago, numerous 10-20 mile trips
LT Headers ~ Nov 20th, 700 miles ago, still using stock 02 sensors
New plugs and wires with the headers

And the timeline for the CEL's:
Drove it like a rented mule to try out the new DR's
drove 10 mins normal to fill up
after fill up drove to work ~3 mins
Set for a few hours, started up and drove to town - 10 mins freeway
noticed rough idle in town
drove around town ~ 10 mins
got back on the freeway, CEL came on
drove for another 10 mins on freeway home

What do you experts think? Is it just wishful thinking on my part that the CEL is from contaminated gas? Why didnt I have issues immediately after installing the headers or the tune from ECS?

***EDIT***My battery is also failing. I will be replacing it this week, I have to jump start nearly every time I get in it now.

GoldenFlame

Those are slow response codes and they ARE from running longtubes.. Mine didn't post right away either and its annoying but I tuned them out with HPTuners

TX Z06 02

DAMMIT! I just got my ECM back from ECS a month ago. I dont want to go through that hassle again

JR-01

JR-01

A bad battery can cause a lot of problems. Replace it and make sure it's fully charged before you drain the fuel.

TX Z06 02

Will change the battery first before any further troubleshooting. Thanks everyone.

And sorry, 8Vette7, didnt mean to come off rude. The engineer in me makes me overly inquisitive is all.

Motorhead-47

Very likely is in the tune....call ECS and talk to them. Both of those codes are for "Sensor 1", both the left and right banks. You need those o2 sensors in the loop to set fuel trims properly or the car will run like poop. How long had you run the car with the new tune before getting the CEL? Minutes, Hours, Days???

99mallett

My engine is heavily modified and I pop O2 sensor warnings on rare occasions where I start it up cold and drive it a little too "briskly" without a couple of minutes of proper warm up. This is fairly common with LT headers & tune, as it tends to make the engine run a little leaner.

UM Rebel

Fix battery issues first before any other steps. Failing/discharged battery can cause all kinds of strange issues. LDCM, RDCM, EBCM codes just to name a few. Also advise recharging a badly run down battery with it disconnected from car's electrical.