O2 sensor cleaning

[Herrett]

Just had another scan related to a check engine light and got this code P0171. O’Reilly said it was probably related to an O2 sensor. They suggested I buy 1 of the two products they sell before I replace the sensors (see attachment). Any thoughts on whether the products are of any value or whether the products could cause problems.

Thanks

Robert

 

[Kernal]

What model/year 80 series do you have?

Any recent changes in how the engine runs?

Any recent work done around the engine bay, just before the code popped up??

Could be from an air/vacuum leak, check the large air intake tube that runs from the air filter box to the throttle body for cracks between the pleats This often happens when the air filter is replaced and the lid is lifted straight up bending the old hard rubber tube until it cracks. Also check other vacuum hoses to see if they're cracked or disconnected.

Maybe start there and report back.

 

[Herrett]

1997, runs really good. I had an auxiliary wiring harness catch on fire and was addressed by my mechanic a few months back.

 

[Kernal]

So did the code pop up after that work?
Other codes before or after that work?
Which harness, where, for what?

 

[Herrett]

No other codes. This one popped up roughly a month after replacing an auxiliary wiring harness.

My question was about the cleaning additives.

 

[Kernal]

Understand, reason I mentioned to check for any air/vacuum leaks because those are common and usually easy to fix. and the cleaning additives won't help if the cause is a vacuum/air leak. Might help if any fuel injectors are severely clogged. Either way, they shouldn't hurt so if you haven't used an injector cleaner in a long time, give it a try.

IME and FWIW, whatever the bottle says, like "add to (up to) 20 gallons" for example, I generally cut that number in half if I'm adding an injector/combustion chamber/valve cleaner. But if you're concerned call the manufacturer of whatever product you choose and ask what is the minimum amount of gasoline that needs to be in the tank when using their cleaner.

Generally those cleaners are all very similar, IME the difference being in the amount of PEA or similar chemicals in the product.


You may also want to clean the MAF sensor using an appropriate MAF cleaner.


Where was the auxilary harness installed, for what purpose, spliced into what/where ??

 

[Herrett]

Thanks for the detailed response. It was a light force wiring harness. Never gave me any trouble until after removing security system at dealership in Ft. Smith. My valet button crumbled and we couldn’t unarm the LC. So had it towed to dealership. I was hunting 2 hours away from home. Expensive nightmare.

 

[BILT4ME]

I typically recommend NOT pouring stuff in the gas tank, down the intake or in the oil.

These things can wash loose stuff you don't want coming loose and it will mess with sensors, cats, plug injectors, and cause bearing damage (added to oil)

Fleet trucks don't add stuff in millions of miles.
Buy quality products on the front end and do regular PM.

You can do whatever you want, but it's not uncommon to need to replace O2 sensors.

The more you drive it, the better stuff works.

 

[Herrett]

You were right not to recommend the cleaners. It was a cracked hose. All good now.