QuestionHello
I have a 2000 Chrysler Seabring LXI. I have not been able to pass inspection due to a engine not ready, I have ran a diagnostics test through our local AutoZone Parts Store. I get a code P302 # 2 cylinder misfire. Can anyone help me.
I have replace all 6 spark plugs and wires and distributor cap and rotor, along with all 6 fuel injectors, and even EGR sensor. Please help.
AnswerHi Henry,
It appears that you changed out most all of the possible parts that would cause a single cylinder misfire. One thing you might try is to buy a can of spray starter fluid. Then with the engine idling spray very small spritz's of fluid around the circumference edge of the upper intake manifold and listen after each spritz to hear an rpm increase or decrease which may well indicate the location of an intake manifold air leak. You could try retightening the upper manifold bolts in that case (13 foot-pounds).
I answered a similar question about cyl #3 and a generic (all cylinder) code, P0300 with the following response (with the proviso that because of your single cylinder situation I would tend to give less weight to those aspects that would impact all the cylinders):
"The codes are based upon the detection of minor missing which causes subtle differences in the rpm as each cylinder fires to produce its rotational input (crankshaft speed sensor is the detector involved). The Chrysler troubleshooting manual lists the possible causes as:
secondary ignition wires, puel pump or fuel filter, injector harness connectors, ignition coil circuit, spark plugs, mechanical engine problem, contaminated fuel, water in fuel, PCM grounds, Injectors, Restricted exhaust, intake restriction, PCM, evap system, EGR system, Air gap at high rpm's, damaged sensor trigger wheel. That is quite a list!
The approach suggested is to check all electrical connectors and wiring, then do the tests in the following order:
secondary ignition
fuel delivery
engine vacuum
PCM power and ground connections
engine mechanical
The first one uses an engine analyzer scope to look at the high voltage pattern, then spray water on the cables to see if it changes. The possible repairs: individual spark plugs, coil or cable replacement
The second one involves pressure measurement and from there a variety of possible solutions
The third involves reading the intake manifold vacuum to see if it is steady at between 13 and 22 inches of HG. and if not the suspects depend upon the pattern shown by the gauge.
The PCM involves checking various wires at the PCM plugs
The last involves engine compression testing and a variety of other mechanical checks.
So I guess that beginning with the ignition wires makes sense unless you have a scope and the experience/knowledge at interpreting the patterns. You might try looking at the wires in the dark with the engine idling, then also spray some water mist on them to see in either case if you see arcing which would be a sign that the wires' insulation is breaking down. Then measure the coil resistances. If it passes that, then focus on the fuel filter and pump.
The code pointing to cyl #3 means the general problem is affecting that cylinder more than the others, but the approach to it is identical to that for the general misfiring problem, perhaps with a focus on #3. But the 0300 code is probably the controlling factor (involving multiple cylinder misfires rather than just one).
I can't give you any personal experience with this situation, unfortunately.
I'd be interested in learning what you find to have been the solution."
You might also try disconnecting the battery for a few minutes before the next check to be sure that stale fault codes are erased.
Other than all the above, I can't give you any other ideas.
Roland
PS I listed all the codes in the subject line for the purpose of providing a full list of the key codes that others might find to be present.
