Q: 5.4l. went from 3&5misfire,to multi misfire,to low fuel prsr bnk 1to limp mode now.tried comp rest,still limp.have code reader me

asked by on

Went from codes misfire cyl 3&5, to multiple misfire, to low fuel pressure bank 1 to flashing o/d light with code for a valve in transmission now and is in limp mode now. This all started with changing the spark plugs. I've checked c.o.p and injector connections. I see on the 4.2&4.6 that the plugs have diff suffix for diff cylinders but not on this 5.4. . Tried resetting comp and better fuel, new oil & filters, mass air sensor & throttle body been cleaned also

My car has 191742 miles.
My car has an automatic transmission.

If the problem started literally upon start up after installing new plugs I would first suspect a problem with the plugs, or something was damaged during the work or something is not properly connected. Of course, coincidences are possible, such as a failing fuel pump (you refer to a low fuel pressure indication), but I would just take it from the top and re-confirm all work done in replacing the plugs (including be sure you have factory OEM approved plugs), and test all connections that might have been disturbed in replacing the spark plugs. If the trouble does not come in to view, a mechanic will pinpoint it for you, regardless of the cause. To obtain that service, please simply request a misfiring diagnostic and the responding certified mechanic will get this diagnosed and resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic.

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. 5.4l. went from 3&5misfire,to multi misfire,to low fuel prsr bnk 1to limp mode now.tried comp rest,still limp.have code reader me

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: Lost my brakes

Brake issues are extremely delicate and very hard to diagnose without an onsite brake inspection. However, the problem you're describing is common when an issue with the master cylinder exists and air finds a way into your brake lines. When...

Q: The yellow exclamation light and emission light is on my dashboard.

The yellow exclamation light is coming on for the brake fluid sensor is picking up the level is low. If the fluid was low before and you topped it off and now the light is on, check the brake fluid...

Q: Turns over but will not start and has a strong odor of gas.

Check the location of where the fuel smell is emitting from on your vehicle. If the fuel smell is coming from the fuel tank area, then the fuel pump, fuel line, fuel filter, fuel fuller neck, charcoal canister, or the...

Related articles

Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.