Added Gumout, Now Car Studders and Shuts Off

Greetings All,

I have a 2004 Chrysler Crossfire. I noticed that my engine would studder when the gas guage got in the red so I added a bottle of Gumout. I then added 11 gallons of gasoline. Now, the engine studders all the time, almost cuts off, has little power and the Check Engine light is on.

Does anyone know what could be happening or can someone recommend what I should do?

Thank you,


Now that the check engine light is on, you should be able to guess what to do. It involves a tow truck. Don’t pour any more paint thinner in the tank, ever. I don’t care what the label on the can says, Gumout is paint thinner. Don’t let the gas tank go below a quarter either. You may damage the fuel pump if the tank gets too low. (After reading the posts that came after mine, maybe I’ll actually read the label on the can.)

Replace the fuel filter and spark plugs. If these have been done recently, perform a fuel pressure test.

Probably just a marginal fuel pump on it’s way to being a dead fuel pump. I doubt the Gumout had anything to do with it.

Check Engine light is on

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

Went to Advanced like you suggested and they plugged in.
The codes are:
PO304, PO302, PO300, PO154, PO134, PO104
Please let me know what you think. - Thx!

Agree. Gumout and all it’d cousins have been around a very long time. Never heard it
caused any problems like this. Never saw that it did any good either. I try to keep
track of key words people (including myself) use that point in a direction. Stutter
sometimes going to stutter all the time says consider fuel pump.

I would start with the issue with the MAF sensor circuit. Fixing that may clear up all of the other codes too. Start by checking the wiring to the MAF and then cleaning the MAF sensor wire (the bare wire inside the air intake hose).

I agree with tardis that the problem with the MAF (Mass Air Flow) Sensor might be the first domino which causes all the other sensor readings to show faults; or, there might be multiple causes.
The DTC P0104 is defined as: MAF signal intermittent. This intermittent signal can be anywhere in the MAF sensor CIRCUITRY; such as the wiring or wire connectors. It could be in components (the MAF Sensor, or the ECM (engine computer). Check (have checked) the wiring between the MAF sensor and the ECM. A “wriggle test” with an electrical multimeter connected to the circuitry, with the engine running, would be one test. It’s up to the mechanic to use other tests, other than a wild tossing of parts.
DTC P0134 and P0154 say that the front oxygen signals are low and slow. DTC P0300, P0302, P0304 are for cylinder misfires. These, all, could be caused by the P0104. Concentrate on that code, first.

Sopus Products makes a lot of products with the name ‘Gumout’ on them. Which one did you use? Give us the exact name on the bottle.


Its Gumout Concentrated Fuel Injector Cleaner. It said to add to near empty tank then add up to 21 gallons of gas. I added about 12 gallons. - Thx

Hi All,

It got fixed and here is what happened:

The mechanic changed the spark plugs and it did no good. Then he borrowed a coil pack and started swapping it around and it did no good. Then I told him again what happened again, reminding him that the problem started within 5 miles of adding the Gumout, so he put something in the tank called CFoam (or Sea Foam). Within a few miles, the problem was gone.

That whole exercise cost me about $300.00. Guess what I think of Gumout.

Thanks all for leading me the right direction.

Thanks Everyone!

I’m glad you mentioned the Sea Foam. Sometimes, we don’t get to hear about the solved problems. I still haven’t looked at a Gumout Concentrated Fuel Injector Cleaner label.

This is also a good opportunity to remind people to read and follow the instructions written on products. I had to explain how to use the contact cement that had to be brushed on. They would complain about the bad can of glue. When they were shocked that I told them to brush it on both parts and wait for it to dry to the touch before carefully matching the parts up, I knew that they didn’t bother to read anything.

However, if the tank holds 20 gallons or more and you then filled it up with the 12 gallons, you did well.