SUV lags when trying to accelerate. Engine rpm goes up with hesitation but speed hardly increases. Check engine light blinks, ac blows hot. Random misfire, cylinder 5/6 misfire codes.

SOURCE: 1999 toyota camry

Take it to autozone and have them to pull a code on it.It sounds like O-2 sincer

SOURCE: 2003 Crown Vic Misfiring after acceleration

I just came up with that exact issue in my 2003 with 98K police crown vic. And the last time I had this issue in a 2001 police Crown vic it was the crank shaft position sensor. A $20 part and about 30 mins to put it in. located near the bottom of the engine. I had to un bolt the A/C compressor and push it out of the way a few inches to get to the sensor. If you have about 100K mile on it and its an idled heavy police car, this sensor should be changed out anyway. It can leave you on the road dead and some dealers have a hard time find out whats wrong as the OBD 2 does not see it as a problem when it goes bad or becomes touchy as I think mine is.

honeymokey

• 3113 Answers
• Posted on Jul 24, 2009

SOURCE: 2004 Isuzu Rodeo 3.5ltr 4X4 hesitation/misfire acceleration

The upper intake gaskets may be leaking. They are made of plastic and metal and will leak air. Do not remove the cover on very top of manifold when changing.

Mike Butler

• 6674 Answers
• Posted on Aug 23, 2009

SOURCE: 2004 subaru forester, 99,000 miles. Check engine

Drop in to an Autozone, or Pep Boys, or similar big parts store & they will usually scan for codes free. This will hopefully eliminate all the guess work, or at least point everyone in right direction for better diagnosis. If not obvious from codes what the problem is, get back to us and we'll help you out.

Testimonial: "Thanks for the great suggestion . I'll have Autozone read the codes on Monday. Thanks again!"

ZJ Limited

• 17989 Answers
• Posted on Apr 25, 2011

SOURCE: code reads "random/multiple cylinder misfire

Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.

A P0300 diagnostic code indicates a random or multiple misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.

Symptoms may include:
the engine may be harder to start
the engine may stumble / stumble, and/or hesitate
other symptoms may also be present

Causes: A code P0300 may mean that one or more of the following has happened:
Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
Defective computer

Possible Solutions:
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.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

Hope helps.