Question about 2003 Toyota Celica

1 Answer

When the accelerator is depressed the engine hesitates & sometimes dies. i changed the plugs,ohm'ed out coils(cop) with same output on all within spec,put in hi-octane gas,and checked hose going from air filter to mass airflow sensor,checked for leaks around intake manifold. seems to be alot better but not sure what may have helped the most! any other suggestions? autozone ran diagnostic and came up with p301 code

Posted by on


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that gotĀ 5 achievements.


    An expert whose answer gotĀ voted for 20 times.


    An expert who has written 20 answers of more than 400 characters.

  • Expert
  • 65 Answers

It was probably a lot of things that helped. With that code on is the check engine light on? the engine may be running to rich or too lean , lean it will run hot too. check the other sensors like the O2 sensor. other than that it may be the fuel filter or really dirty injectors, or a faulty injector. hope this give you some options

Posted on Jun 27, 2009


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

My expedition skips on low acceleration and stops when accelerated hard why

What you have is one of two things. You have a sparkplug that is bad and or a cop (coil on plug) that is bad. A good way to figure this out is to go to autozone and have them do a code check. Sometimes a " check engine" light will come on and sometimes it wont. My check engine light never came on. It was missing but after aceleration or high rpm the miss would go away. I changed both the cop and spark plug and problem fixed. By the way coil on plugs are expensive. I ordered mine on the internet and saved over 75%. Best wishes and hope this solves your problem.

Mar 18, 2015 | 1999 Ford Expedition

1 Answer

Why does my 2006 5.4v8 expedition still not accelerating after fixing the engine code that shows bad coil number 6 even replaced plug ?

Need to replace All the spark plugs,All the coils
& All the oxygen sensors,clean the maf sensor

Usually with all the cylinder misfires from bad coils,
your exhaust converters are ruined

Jul 27, 2014 | 2006 Ford Expedition

1 Answer

When I put my 2003 GMC in drive it hesitiate. But when I put it in neutral it calms down

When a vehicle is in neutral there is no load the moment you put it in gear then there is a load,If you hesitate in gear and try to accelerate and it hesitate you have a misfire,sparkplugs,sparkplug wires,If you dont have coil wire the the COP (coil on plug) either way you have a misfire

Nov 08, 2012 | 2003 GMC Envoy

2 Answers

When i accelerate car makes a popping sound, hesitates and then takes off

99% of the time this means you have a ignition misfire, and almost always was is a plug cable. Since you have COP's (coil on plugs) on the 4.6 Northstar, it is probably a little more complicated, especially if you are not getting a check engine light (yet)-carefully open the plug wells by removing the cover and the COP's one by one, and look with a flashlight (and possibly a mirror) down the wells for oil puddles at the bottom. This could cause a coil misfire. Or you could wait for a check engine light to come on and have it scanned for a code, since this will give you the actual cylinder misfire location. Depending on how long it has been since it was last done, you may be due for new plugs, a cleaned MAP sensor, air filter, and general important preventative maintenance like a trans service and oil change.

Apr 18, 2011 | 1998 Cadillac DeVille

1 Answer

2001 lincoln ls v8 keeps misfiring. Changed valve cover gaskets, all spark plugs & coils & boots! Compression was hit & miss. New engine about a yr ago (they said the tooth broke- mayb bs)....

If you had any COPs short out, it may have taken out the dirvers in teh PCM. Get a used one from if you do.

Usually a check engine light comes on and some codes are set.

Dec 22, 2010 | 2001 Lincoln LS

1 Answer

The engine hesition sometime 04 expedition 5.4

Most likely you have a bad COP (Coil On Plug) .
Maybe more than one. Very common ford problem for last 12 years.
If you get a MIL Light on the dash (the wrench),check for a PO300 Code.
A PO304 would be coil #4,PO306 #6 Etc.
Cyl 1 thru 4 on pass side
Cyl 5 thru 8 on driver side,front to back

Also hills cause a hi engine vacuum and thus a possible EGR Valve going bad. You can unplug the vacuum lines and plug, to diagnose that issue.

Also leave the EGR disconnected if your working on coil issues. Just note the MIL light will stay on all the time,and remember to check your 300 codes if you feel a hesitaton or miss.

Jul 28, 2010 | 2004 Ford Expedition

2 Answers

Car hesitation

sounds like the coil pack is failing or you could just have water in your fuel.... buy a couple bottles of gas line antifreeze (it sucks up water) and add them to your tank when you fill up.... if that doesn't fix it it is likely the coil pack

Apr 16, 2009 | 2004 Chrysler Sebring

2 Answers

How do I change the rear spark plugs on a 1998 Olds Intrigue?

if they unscrew easy then your good to go. have you ever changed plugs before? sometimes if they are hard to get to you need the right socket extension,swivels. probably the best tip i can give you is that if a plug doesnt come out leave it in, it costs lots of money to get a stuck plug out of engine. let me know if you need help

Apr 01, 2009 | 1998 Oldsmobile Intrigue

Not finding what you are looking for?
2003 Toyota Celica Logo

196 people viewed this question

Ask a Question

Usually answered in minutes!

Top Toyota Experts


Level 3 Expert

76846 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22246 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8547 Answers

Are you a Toyota Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides