2003 pt cruiser turbo misfire PLZ help

[patrickjudkins]

i just posted below on an overheating prob here is another problem we have had for over a year on the same car...its a 2003 pt cruiser gt and its been misfiring for a long time now, it shows the code p 0304 which is random misfire on the 4th cyl... here is what ive tried, replaced spark plugs(3 times all different types) replaced the coild box which sparks to all 4 cyl, ive tried replacing the spark plug wires, ive cleaned the number four injector and even swapped it with the number 1 injector. what am i missing here i thought i had covered all the grounds, ive even gone so far as to pressure test the number 4 cyl as well as the other 3 cyl's all have good pressure so head gasket isnt blown no bad rings i cannot find anything wrong, ive tried additives for injector cleaners, paid 89 dollars for a real intake system clea, took the exhaust manifold off to see if maybe sumthing was blocking the exhaust tube for the # 4 cyl, did the same thing with the intake, changed air filter, we only run premium gas because thats what it calls for, i just cannot figure out what it is, neither can any shop ive ever taken it to... we see about 16 miles to a gallon on the freeway at 70 miles an hour and the car shakes so bad when your sitting still it almost makes sick, and is almost embarrasing to sit at a light cuz it is so obvious that there is a problem. we will be leaveing on vacation in 8 days and gone for 2 weeks i dont really need this fixed too badly but would like sum input on it. also id liek to add that the car is bone stock not a single thing has been changed and also the headlights and dash lights dim and brighten with the misfire of the motor, every time it misses the lights dim. please help

[Hooligan]

How many miles do you have on your PT?

[patrickjudkins]

it has about 70k on it i think the exact yesterday was 70497

[quicksilverdon]

Spray starter fluid along intake manifold seam - if it smooths out idle, it's a manifold gasket leak.

[patrickjudkins]

should i spray it were the manifold meets the engine or the seam acouple inches from the motor were the manifold starts to curve, also should i try were the throttle body meets the intake manifold, i will definitly try this in the morning i cannot find anything else this maybe the answer it does kinda sound like there is an air leak i thought maybe a vaccum hose or exhaust leak but now that i think of it it could very well be an intake manifold gasket. thank you for your thoughts.

[quicksilverdon]

Shouldn't be at the throttle body, but along the seams of the intake manifold.

[VNT]

See if a dealer has ever replaced the manifold gasket between the head and the lower manifold.

On the 03 Turbos it is a common problem, you develop a vacuum leak and the car will not idle properly. Guess they had bad gaskets.

[patrickjudkins]

ok i wen tout there today with a shiny new can of starting fluid, sprayed it down the drivers side of the intake manifold and after less than a second of spraying the idle goes up then the car tries to die like im flooding it or sumthing, but the idle definitly changes when i spray down that tube but doesnt down any other tube, im thinking this is definitly my problem, so i have ordered new gaskets for all the things it looked like i will have to take off. please post and confirm that this is my problem, you said it would smooth out the idle and it seems liek it may for just a brief second but then it tries to die. thank you so much