Q: loss of power sluggish
My XL Denali has a given p0121 code due to intermittent loss of power - not complete loss of power. It’s sluggish when the car idles - like at a stop sign. This happens about once or twice a week. Do you have any suggestions on how to fix this problem?
Recommended Services
| Clean Throttle Body | $109.17 - $370.59 | Get a Quote |
| Loss of power Inspection | $94.99 - $114.99 | Get a Quote |
I recommend inspecting, then cleaning the throttle body if any deposits are found. It’s important to do this with key off and disconnect the electrical connector to throttle body. Do not put your fingers in there until it is connected. Push throttle plate and if it sticks or binds replace it. Perform the throttle relearn procedure after cleaning. A scan tool is used to clear any diagnostic codes set during this procedure. If you would like this taken care of, an experienced technician with the right tooling, such as one from YourMechanic, can diagnose the loss of power issue and let you know exactly what actions are needed.
The statements expressed above are only for informational purposes and should be independently verified. Please see our
terms of service
for more details
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
What others are asking
What functions are on the turn signal and headlight stalk?
Several key functions are built into this control, including the following: Turn Signals: Flip the stalk up or down to activate your left or right turn signal. Headlights: Turn the control to activate parking and taillights, and headlights. AUTO: Choose...
Car slips and grinds
The fluid level in the transmission (https://www.yourmechanic.com/article/how-do-you-know-when-your-transmission-fluid-needs-to-be-changed) may be low. The fluid level needs to be checked and topped off. If the fluid level is correct, then the CVT transmission may need to be replaced. You may want to enlist...
Opinion on a 2013 Mini Cooper
I'm not a fan of them. My neighbor has one and to me that thing is so cheaply made. The wiring is so thin. Hers is eight years old and everything is shorting out. The thin little wires that they...
Air conditioner blows hot air. 1995 Mercedes-Benz E300
Hi there, thanks for writing in about your 1995 Mercedes-Benz E550. This could be a variety of issues, such as no pressure or low refrigerant levels, a bad compressor clutch, or a compressor not engaging correctly. Check to see if the...
Brake light issue
I would suggest checking first to see if the bulbs need to be replaced. Secondly, check the contacts in the rear tail light sockets. There should be two contacts, one for tail light and one for the brake light. Test...
Tail lights and running lights won't work - 1996 Toyota RAV4
Hello - check first for a blown fuse since it sounds like all your "rear" lighting has failed. A bad ground for the rear lighting (or broken ground wire) could also cause a complete rear of the vehicle lighting issue....
I deflooded my 04 RX8 and got it started. It sputtered and stalled, then was able to keep it running for about 5 min or so.
Hi there. Usually when the motor becomes flooded or has a hard time maintaining a solid idle, it's caused by either a vacuum leak or a malfunctioning idle control valve (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-idle-control-valve). However, this issue may also be caused by bad...
Would a faulty alternator cause smoking from under the hood on the passenger side?
If your alternator is failing, this can definitely cause it to smoke depending on how badly it has failed. When an alternator fails, the bearings inside usually have failed to a point that causes them to whine severely and, depending...
What are the best 50/50 antifreeze options to use for my car? 2002 Honda Accord
Hi there - there are pretty-much just 2 issues when selecting engine coolant (https://www.yourmechanic.com/article/5-commonly-overlooked-vehicle-maintenance-items-by-toby-schultz). First question is "What "type" coolant should I buy?". Glycol-based coolant tends to be the green stuff. Low-phosphate, for all aluminum engines is pink or orange....
Related articles
How a Modern Engine Works
You You turn your key in the ignition, and the engine fires up. You press the gas and the car moves forward. You take the key out and the engine turns off. That’s how your engine works, right? It's a...
Symptoms of a Bad or Failing Thermostat
Common signs include the temperature gauge reading being very high or changing erratically, engine overheating, and coolant leaks.
How to Install a Camshaft
Over Over the years, engines (https://www.yourmechanic.com/article/how-a-modern-engine-works) have evolved in so many ways. Most of the changes or improvements that have been done revolve around creating better performance and fuel economy, without making the engine larger. One of the biggest changes...
Browse other content
Maintenance
Cities
Services