While driving, engine loses power and backfires will not accelerate,stop engine little while start up and engine runs ok

have you replaced the coil pack/ignition coil. remove the plugs and check to see what colour they are this will help determine what could be wrong. you could have carbon build up this would give pre ignition ie backfire this would limit the the bang . use some sea foam this has worked in all engines i have had. take the plugs out an pour some in the cylinders and put the plugs back in. and leave for an hour. then use the rest as indicated using the air intake vacuum line, should remove the build up.

tmiming belt, you need to change it!

Check fuel pressure

If it is running bad enough to be backfiring, the Check Engine light should be on. I would start with scanning the engine computer for fault codes.

I know you mentioned the EGR valve has been replaced, but you may have a bad 'new' part. I know the car is electronic, but has anyone checked its ignition timing (timing belt been looked at, I know it only has 77k on it). Is the fuel pressure regulator OK and it vacumm supply?

Most likely ignition. Check fuel pressure while driving,with a gauge taped to windshield.

Sounds like you have a vacuum leak somewhere causing the engine to flood.Check all hoses coming fron intake manifold.

Ok, there are many issues here that you will need to inspect. I recommend changing the fuel filter and pump as well. this will fix the hesitation. the intake and exhaust manifold gaskets will need to be replaced as well. this will stop the backfiring.

I also recommend checking and running a teat on the PCV valve and inspect the PCV hose as well. it could have a leak or a small crack on it.

Check the air filter and change if needed. this will help with acceleration issues as well. Next, i would run a check on all plugs and the complete wire set as well. change if needed.

Inspect the injectors for leaks and lose wires. make sure they are in good condition. replace any injectors that isn't firing properly.

Ok, there are some sensors that you will need to check as well. i will list them below.

SENSOR CHECK LIST--

1. Check the O2 sensors for worn wires.
2. Check the MAFS(Mas Air Flow Sensors) Check for Damaged, Loose, or Faulty Mass Air Flow Sensor or Circuit.
3. Check the Air Cleaner Temperature Sensor. this sensor could be damaged ro have loose wires. check accordingly.
4. Check the Throttle Position Sensor. this device could be connected wrong or it may be faulty as well. replace if needed.

Be sure and inspect all the above and repair any problem spot you ruin across during your inspection.

Please rate and god bless:)

disconnect exhaust ,muffler or cat may be stopped up

Your timing belt could be broken. You want to have this checked as soon as possible to prevent any further engine problems.

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