PO300 Code , Help Please
Jul 1, 2015, 11:04 AM
#1
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PO300 Code , Help Please
Changed, Plugs, Wires & Coils,
Car pulls fine in 1 & 2nd but hesitating in 3rd & 4th gear, compression 180 across, could it be a cat or Egr Issue
Car pulls fine in 1 & 2nd but hesitating in 3rd & 4th gear, compression 180 across, could it be a cat or Egr Issue
Jul 3, 2015, 04:45 PM
#4
P0300 shows that a random misfire happened on more than 22 of the last 1000 engine revolutions during the last drive cycle. Look at the following possible causes in sequence. The most likely are shown first:
1. Check your plug condition/gaps, leads (no breaks in insulation) and coils (no cracks and resistance < 19kOhms between lead end and coil plug connectors) and make sure you have a fat spark on each.
2. Check your crankshaft position sensor and trigger wheel are not damaged (missing or bent teeth) or dirty. It's behind the timing belt drive pulley on the passenger end of the crank shaft.
3. Check your AFR is not too lean or too rich (Long Term fuel trims are not greater than +/- 12.5 and Short term O2 trim not greater then +/- 20). This could be due to a boost leak or loose vac lines behind the intake manifold.
4. Check cylinder compression pressures are not below 138 psi
5. Check timing belt tension and make sure it has not skipped a few teeth.
6. Check your EGR valve has not failed.
1. Check your plug condition/gaps, leads (no breaks in insulation) and coils (no cracks and resistance < 19kOhms between lead end and coil plug connectors) and make sure you have a fat spark on each.
2. Check your crankshaft position sensor and trigger wheel are not damaged (missing or bent teeth) or dirty. It's behind the timing belt drive pulley on the passenger end of the crank shaft.
3. Check your AFR is not too lean or too rich (Long Term fuel trims are not greater than +/- 12.5 and Short term O2 trim not greater then +/- 20). This could be due to a boost leak or loose vac lines behind the intake manifold.
4. Check cylinder compression pressures are not below 138 psi
5. Check timing belt tension and make sure it has not skipped a few teeth.
6. Check your EGR valve has not failed.
Jul 6, 2015, 02:15 PM
#5
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Location: san francisco, ca
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nice tshooting list. 
P0300 shows that a random misfire happened on more than 22 of the last 1000 engine revolutions during the last drive cycle. Look at the following possible causes in sequence. The most likely are shown first:
1. Check your plug condition/gaps, leads (no breaks in insulation) and coils (no cracks and resistance < 19kOhms between lead end and coil plug connectors) and make sure you have a fat spark on each.
2. Check your crankshaft position sensor and trigger wheel are not damaged (missing or bent teeth) or dirty. It's behind the timing belt drive pulley on the passenger end of the crank shaft.
3. Check your AFR is not too lean or too rich (Long Term fuel trims are not greater than +/- 12.5 and Short term O2 trim not greater then +/- 20). This could be due to a boost leak or loose vac lines behind the intake manifold.
4. Check cylinder compression pressures are not below 138 psi
5. Check timing belt tension and make sure it has not skipped a few teeth.
6. Check your EGR valve has not failed.
1. Check your plug condition/gaps, leads (no breaks in insulation) and coils (no cracks and resistance < 19kOhms between lead end and coil plug connectors) and make sure you have a fat spark on each.
2. Check your crankshaft position sensor and trigger wheel are not damaged (missing or bent teeth) or dirty. It's behind the timing belt drive pulley on the passenger end of the crank shaft.
3. Check your AFR is not too lean or too rich (Long Term fuel trims are not greater than +/- 12.5 and Short term O2 trim not greater then +/- 20). This could be due to a boost leak or loose vac lines behind the intake manifold.
4. Check cylinder compression pressures are not below 138 psi
5. Check timing belt tension and make sure it has not skipped a few teeth.
6. Check your EGR valve has not failed.
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