Help multiple mis fires, system is too lean, and intake sensor.

I've got multiple misfire codes.

P0300
1083
1085
1351
1353
1348
1074
1071
0102

I understand the intake sensor can be cleaned. I've also replaced the spark plugs with some bosch spark plugs about 10k miles ago. I've also checked for any cracks in the intake boot and didn't find any. Also used some manifold cleaner to test for vacuum leaks (if I should use a different spray please let me know).

The only things I can see happening are the coils (which is unlikely in my mind). The fuel filter and the fuel pump, but before I go spending hours and money on stuff, I was wondering if you guys can help me pinpoint the problem.

The symptoms happen exactly in this pattern.

Car cold starts just fine, no light, no rumble (70 degree weather).
Drive for about an hour, light comes on, starts to get rough idle (from misfires).

So something has to be heating up somewhere and causing the failure right?

Prior to the misfires and running rich, I filled up with shell V-power, that's it.

You can't check for all the cracks in the CCV without taking it out, and I doubt you spent 3 hours checking it.
You could do a smoke test.

And some cracks aren't visible until you bend it. When i had the same problem as you, I found the crack because of a moisture patch, when I touched it it bent over and revealed the crack. After taking apart the ccv, multiple cracks were found. If your car is 10+ years old, more than likely the rubber has rotted.

Mine was running rich however.

Are you sure you got those codes right? You listed P1071 and P1074, but I think you meant P0171 and P0174. The codes I think you meant are codes to denote a lean condition, and lean & misfire can have the same cause.

Basically, you have a vacuum leak that makes the car run lean and also makes it misfire.

MISFIRE means that the expected work was not performed, or the work that was performed was below the expectation. If your crank is getting from check point to check point in X-amount of time, and something happens and the next checkpoint is not reached within the timeframe that is expected, then the work is not performed and a MISFIRE is stored. Lean can equal misfire. You do not need bad spark, you only need the lack of expected work.

P0102 gives me trouble though. I believe this one means the MAF is unhappy. I have not looked it up, but if I am right then the MAF can be feeding the lean condition that results in misfires.

The MAF tells the computer that the condition of the intake air is and the computer alters the fuel delivery based on what the MAF has to say about the air -- dense or lean air will require different amounts of fuel to maintain a mixture ratio of 14.7 parts of air to a part of gas. If the MAF is saying that the air is thin, then the computer will cut back on the gas, BUT if the air really is not thin then the resulting fuel mixture in the exhaust will be lean. Before you jump on the MAF, double check the code meaning. And if the MAF is reporting a code, then it can be the cause of the lean and the misfires.

Guess I should do that after the rain is over. But honestly, should I really get CEL after an hour of driving every time rather than immediately if the PCV was the issue?

Originally Posted by slimg00dy

Guess I should do that after the rain is over. But honestly, should I really get CEL after an hour of driving every time rather than immediately if the PCV was the issue?

What?

Who said anything about PCV?

JD, you could be right, it could be 0171 and 0174, the system is running lean in both banks.

TRD, I'll check both secondary and primary (intake) vacuum for cracks.

Mine is also running rich. According to P0174 and P0171.

Originally Posted by jdstrickland

What?

Who said anything about PCV?

Sorry meant CCV

Originally Posted by slimg00dy

Guess I should do that after the rain is over. But honestly, should I really get CEL after an hour of driving every time rather than immediately if the PCV was the issue?

Vacuum leak can occur at any time depending on conditions. In the winter when it really gets cold, the rubber shrinks causing a bigger leak. CEL with these cars a sporadic. Will come on and off, and won't come on when it should and vise versa.

I'm not sure, but your fruit basket has far too many varieties in it, and you are mixing them up.

KISS -- keep it simple stupid

You are adding multiple levels of complexity to a problem you do not know what the cause of is. If the MAF is not behaving itself, it could be the only problem you have. The problem with this diagnosis is that it is almost impossible for you to do at home. You can replace the MAF easily enough, but it is expensive and not returnable. You need to connect your car to the Data Link Connector and a diagnostic computer that can look deep into the operations of the car. The MAF _could_ get drity, but it can just as easily develop an internal circuit failure. The DLC will uncover it, but this means a charge for diagnostics.

The people that charge for diagnostics can also blow smoke into the intake and look for it to come out through the cracks, so this is probably something you should consider doing.

Has any work been done to the vehicle prior to the lights? Check your clamps for tightness.

Check the back of the intake for a couple of things in addition to the usual suspects: torn rubber tubing for secondary air valve control; cracking/torn rubber caps on unused intake vacuum ports.

Apart from visually inspecting the usual suspects, the smoke test is the most effective diagnosis for leaks.

The light came on last night and I was going to check the intake this morning (apart from the check/feel I've done already) this morning but it rained all day.

Okay, so I did a smoke test and you guys are right, the intake boots are deteriorated pretty badly.