Q: I have a code P1399 random misfire
I have a misfire , especially on cold mornings The misfire is worst it gets better when the engine warms up tho . But I'll be driving on the highway and I can feel the random misfire, that aren't so bad but I can feel them .. and it gives a code p1399 . Ive changed the spark plugs, wires , and a 02 sensor . What else do I do? Or replaces?
My car has 158984 miles.
My car has a manual transmission.
Recommended Services
| Fuel Injector Replacement | $400.56 - $3968.30 | Get a Quote |
| Fuel Pump Replacement | $145.32 - $1299.70 | Get a Quote |
| Fuel Pressure Regulator Replacement | $126.81 - $1011.90 | Get a Quote |
| Spark Plugs Replacement | $113.11 - $716.47 | Get a Quote |
| Ignition Cable (Spark plug wires) Replacement | $123.29 - $510.40 | Get a Quote |
| Ignition Coil Replacement | $132.12 - $587.62 | Get a Quote |
| Engine is misfiring Inspection | $94.99 - $114.99 | Get a Quote |
Hello. A random misfire can be caused by many different things such as dirty fuel injectors, a weak fuel pump, a bad fuel pressure regulator, fouled spark plugs or wires, a failing ignition coil or a vacuum leak. To get a more precise diagnosis, I would recommend having a certified professional, like one from YourMechanic, inspect the misfiring problem firsthand so that this can be corrected properly.
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
Advice on working as a mechanic
I'm kind of unique because I learned from my grandfather, who was a mechanic at the corner of Texaco gas station in New York when I was a kid. So I learned hands-on from my grandfather. He wouldn't teach me...
Adjusting the camshaft and crankshaft for the timing chain
I believe the "official" procedure for these M30 engines is to: Leave the tensioner until last Install the chain with the crank and cam sprockets on TDC, and the chain tight on the driver side of the chain Use the...
Truck hesitates to start - 2001 Chevrolet Silverado
Hi. This could be a problem with the mass air flow sensor (https://www.yourmechanic.com/services/mass-airflow-sensor-replacement), throttle position (https://www.yourmechanic.com/services/throttle-position-sensor-replacement), fuel pump (https://www.yourmechanic.com/services/fuel-pump-replacement), or idle air control valve (https://www.yourmechanic.com/services/idle-control-valve-replacement). The mass air flow sensor is a common cause of a problem like this it...
Could my problem be the key? 2009 Honda Civic
Hi there - this sounds like the security system needs a simple reset, similar to what's needed if you replace the battery. Try this: lock the car using the ignition key in the driver door. Let it sit for 5...
Wondering whether I can use prestone 5050 antifreeze coolant instead of fl22.?
While the green coolant or "safe for use in all vehicles" type coolants may be less expensive than what is in your cooling system, I HIGHLY recommend you do not mix them. Different coolants have different chemical properties. They can...
Will using the incorrect ATF on my car cause sensors to fail
With regard to the 2003 Acura TL Honda states in the Owner's Manual, "Always use Honda ATF-Z1 (Automatic Transmission Fluid). If it is not available, you may use a DEXRON III automatic transmission fluid as a temporary replacement. However, continued...
I can't get the ring off the fuel tank to take out the fuel pump - 1992 Chevrolet C1500
Hi there - if you don't have the official GM tool, using a screwdriver and small hammer, and alternately whacking each side to unscrew the large lock ring works with patience and liquid penetrant. For professional assistance, I recommend fuel...
Car jerks when accelerating
What you are describing sounds like a dirty or faulty mass air flow sensor. The mass air flow sensor (https://www.yourmechanic.com/services/mass-airflow-sensor-replacement) monitors air intake as it is mixed with fuel prior to being injected into the motor. This sensor relays vital...
Related articles
The Best Used Cars to Buy If You're an Uber or Lyft Driver
Are Are you thinking of becoming a driver for Uber or Lyft? That could be an exciting career change – you’ll get to meet a lot of interesting people, and if you love to drive, what better way to spend...
The Top 5 Selling Cars in Alaska in 2012
Alaska Alaska requires a different kind of vehicle to handle both the terrain and the wintery conditions. While some of the most popular options for the Alaskan terrain in previous years included options such as the Subaru Forester and the...
Which Cars Last the Longest?
The best cars are ones that last the longest without needing much maintenance. The Honda Civic has low repair bills and can rack over 200,000 miles.
Browse other content
Estimates
Services