"CRC Guaranteed To Pass Complete Fuel System Cleaner"

Anyone have experience and/or success using the subject cleaner???

Nope. But I looked it up and it’s just a fuel system cleaner. With “powerful emulsifiers”. An emulsifier just causes one liquid to break up and be suspended in another liquid. I suspect they mean that it enables anything cleaned out of the system to be suspended in the fuel and burned.

Your gasoline already comes equipped with detergents that keep the system clean. They all do. Unless there’s a specific problem you’re trying to solve, you’re wasting your money. If there IS a problem you’re trying to solve, let us know and we’ll try to help.

It is advertised to enable a vehicle to pass emissions inspection. Money back gaurantee. I have a P0421 even though both sensors have been replaced.

It might be something else, like a fouled spark plug or a catalytic converter problem. What car do you have, how old, what engine, and how many miles? You could pull the plugs and inspect them. If you have a FWD 6-cyl, it could be tough to get them all out. Maybe just the front 3 to see what they look like and check the gap.

They guarantee it’ll work if the problem is related to the fuel system. Your problem isn’t related to the fuel system. But instead is a catalytic converter problem.


2001 Mazda Protege 2.0L 4. New plugs and just cleaned a sticking throttle interior and valve and had a torn MAF to throttle body boot. Replaced two weeks ago and it runs smoother and better.

The plugs were replaced before or at the same time as the oxygen sensors, correct? And the ECU was reset after all that work, too? The ECU will reset itself eventually, but I want to eliminate the reset lag as a possibility.

I had the sensors replaced first. A few weeks later I replaced the plugs. I reset the CEL with my
autel scanner. I drove until all systems but the precat were set but no CEL. It passed smog as I’m allowed one error in California as long as the CEL isn’t lit.

Later, when I started having trouble with the throttle valve sticking shut, I cleaned the housing, replaced the boot and because the battery was disconnected during this procedure the CEL was out. It came back on nine days later.

I’ve turned the CEL off again and plan on doing it several times. I don’t have to smog the car this year as we have every other year to do it and next year I can once again turn the CEL off, run it until everything is set except the precat and pass smog but I’d like to try and clean up the fuel system in the hope of eliminating the precat problem, short of replacing the precat.

I guess I’m just anal about covering the CEL with tape in the interim.

It’s AMAZING how much money gets spent just to make (or try to make) that little light go off…Especially when the “problem” has NOTHING to do with the serviceability of the vehicle…

Find someone who can measure the signals coming from the O2 sensors.
They’ll tell the story.

Contraire Caddyman. The plugs hadn’t been replaced in some time as evidenced from the old ones. P0421 code says the least expensive fix would be the downstream sensor.

I appreciate you chiming in but I’d prefer a knowledgeable solution; if it is other than to replace the pre-catalytic converter.

Have a great day.

The CRC certainly won’t hurt anything so you might as well. The thing about any of those money back guarantees is that they are sort of empty. By the time you’re done spending the time trying to get your money back you’ve probably lost money.

As for the code, its not really something you can get definitive about via internet. Really figuring it out would require an experienced tech with a good scanner to check out what the O2 sensors are actually doing. If they’ve been replaced then you’re basically left with their wires, exhaust leaks (even tiny ones that you might not hear), or the cat.

Yep, they sell 100, 1 of them asks for a refund, CRC’s big money ahead.

Thanks for your input, cigroller. I sincerely appreciate it.
After I’ve cleared the CEL a few more times I’ll give the CRC MAF sensor cleaner a try then the Guarantee stuff and finally I still have 18 months before I have to smog again. Thanks.

Just FYI, I’m pretty sure - though anyone should feel free to give me the correct story if they know it - that the cans labeled “MAF Sensor Cleaner” contain exactly the same thing as the ones labels “Electronics Cleaner.” Except, you generally have to pay a bit more for the one labeled for the MAF sensors. I could be wrong, but I’ve used both on MAF sensors with no noticeable difference.

Thanks. I believe you’re right. If it’ll clean electrical contacts etc. it should also clean bare wire. I’m going with it.

Caddyman, the trouble is, when emissions inspection is required, you can’t get the dang thing inspected with the CEL on. This guy has 18 months to worry about it, but after that he is SOL if that little light is still on.

I’m not totally SOL. In California if the CEL is on the smog inspection stops right then and there. Last September’s inspection passed because I erased everything, drove for a few days, until all systems were OK except the error P0421, but before the CEL had come on. Then I had the inspection and passed with one failure, which I’m allowed. I’m just hoping that in 18 months I can do the same thing again. :slight_smile:

Cig, the only thing I’d suggest in using “electronics cleaner” is that one be sure the can does not also say “and lubricant”. I have a can at home that I use for connectors and contacts that does have that on it, and it does leave a protective lubricant film. I wouldn;t want that on the MAF sensor.

SMB, wow. I have never seen that an I agree completely with your assessment of it. Thanks for the heads up. It would be like me to pick up a can like that and use it without realizing!