Q: After adding fuel additive, SUV performed badly

asked by on

After putting a complete fuel system cleaner additive into my gas tank, my SUV has been having bad performance. There is a rough idle, it hesitates when I accelerate, the muffler putters, and it has stiff brakes. I used the technique of running the gas tank until empty and then refilling it, but that did not solve the problem; it still exists. I am wondering if that means that it was not the additive I put in. Perhaps it is just coincidental that the problem started at the same time as adding the additive. Another thing that is happening since this started is that the check engine soon display on the dashboard is appearing. What is the cause of this problem and what can I do to fix it?

I would suggest checking the EGR valve (exhaust gas recycle). Inside your motor, temperatures can reach 2500 degrees. This is when the EGR valve is needed. When engine temperature is slightly cooler, such as when idling, the EGR valve function is not needed. EGR flow is not needed at idle, and in fact, can cause a rough idle. You may also want to test the distributor and spark plugs and wires. These can also cause rough idle and poor performance when they are old and need to be replaced. If you would like this checked, a certified professional from YourMechanic can come to your car’s location to diagnose the rough idle and acceleration, and can replace your EGR valve if necessary.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. After adding fuel additive, SUV performed badly

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Truck idles rough

This is a sign of a failing idle air control valve. This is a unit that is located on or near your intake manifold that monitors the air intake as it is mixed with fuel prior to being injected into...

Q: 99 sliverado no crank starter and battery checked out good. truck died while i was driving hasn't started sense.

Hi there. Thanks for sending your question to us today. When you have the single clicking sound when turning the ignition, it is typically due to a damaged electrical relay. If your battery tested good (meaning it had enough cranking...

Q: My truck cut off the other day while driving. Battery is new and good, check relay and its good. When I turn the key it won't move?

Have the battery tested professionally if you have not already done so. A battery can show 12 volts while the car is off, but drop to a low voltage while trying to start the vehicle which is a sign the...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...