Question about Cars & Trucks
P0301 Code - Cylinder #1 Misfire
A P0301 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #1.
Symptoms may include:
- the engine may be harder to start
- the engine may stumble / stumble, and/or hesitate, other symptoms may also be present.
A code P0301 may mean that one or more of the following has happened:
- Faulty spark plug or wire
- Faulty coil (pack)
- Faulty oxygen sensor(s)
- Faulty fuel injector
- Burned exhaust valve
- Faulty catalytic converter(s)
- Running out of fuel
- Poor compression
- Defective computer
* This conditions is the same when code is P0302 or P0303.
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.
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Posted on Feb 14, 2012
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Posted on Jan 02, 2017
Try your local library for diagrams and pictures of both engines and that way you can figure out how the wiring goes
Posted on Mar 08, 2009
Concentrate on code 1128, which is basically telling you the engine has been running too lean for a while now, so that explains the misfire codes, which is the rest of them. The main causes of those symptoms is usually a vacuum leak, plugged fuel filter (which you've already changed) exhaust leak, Canister purge system malfunction, or a weak fuel pump. By sounds of yours I'd concentrate on vacuum leak & canister purge system. If you have access to a fuel pressure gauge, check fuel pressure just to be sure, but I'm thinking canister purge circuit.
Posted on Jul 05, 2009
those codes are telling you what you already know you have a miss fire. 300 is multiple and 301 thru 304 is the individual cylinder. could also be a fuel injector,or the injection system, bad gas or fuel filter ,vacume leak,realy it could be alot of things you have replaced plugs gapped correctly checked your wires and replaced your coil. so look to vacume leaks and injectors.
if you dont have a do ityourself book i suggest you invest if you plan to keep the car, and i suggest you dont buy exspensive parts unless your absolutly sure its the problem.easy check for mass air flow with engine at an idle tap on the side with the plastic end of a screw driver if the idle stumbles your mass air flow is going bad. it might not be your only problem only you know when you had the services done on your 10 year old car
Posted on Aug 11, 2010
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