Can exhaust too large cause stall??

[208DSM]

WELL GUYS THE PROBLEM IS SOLVED!! it was my header and exhaust after all. the header was making my coil pack too hot causing it to stall out and the exhaust i came to find out was only 2 1/2in. the guy who sold it to me was wrong. thanks everyone for all the help!!i've done everything possible to solve my stalling problem in my 2G 420A. It has a brand new motor, new o2 sensor, cam sensor, cam sensor connector, crank sensor, coil pack, coil pack harness, fuel pump, fuel filter, cleaned throttle body, new IAC, new TB gasket, cleaned a-32 connector, and everything!! but i do have a megan racing header and 3" from the header back with a hi-flow cat? could my exhaust be too big and no back pressure? header be making something too hot? im running out of ideas and money. it never stalled until i put the exhaust on. i have spark and when it runs it runs GREAT. so please if you have ANYTHING to say that please do, i need all the help i can get. thanks.

 

[dsmjunk]

did you take the hood of yet?

 

[firefighter]

Just because you replaced the exhaust system it will not cause the car not to run.It also seems that you are throwing parts at it.Just because you are taking parts off other vehicles does not mean they are good.Remember you need three things to make a car run,air fuel,spark.Take any of these things out of the picture and the car won't run.If the car starts up and runs that means you have air.So the problem is spark or fuel.Take the car and run it until it stalls then check for spark or fuel pressure.It's a pain in the ass but it becomes a process of elimination.Also you said you had two mechanics check the ECU. How did they check it? The other thing is checking the coil pack.You just don't measure the OHM's without heating the unit up(just like under the hood)because at room temp it might check out fine.This has nothing to do with the headers on the engine.remember the cast iron manifold will get just as hot as the header, it just takes a little longer and it will stay warmer longer.(remember grandma had a cast iron wood stove in her house,once it was warm it stayed warm and continued to give off heat once the fire died down).Hate to say it go back and check everything again.Hope this helps and good luck to you.

 

[208DSM]

did you take the hood of yet?

nah not yet man havent had time haha i will for sure tho

Just because you replaced the exhaust system it will not cause the car not to run.It also seems that you are throwing parts at it.Just because you are taking parts off other vehicles does not mean they are good.Remember you need three things to make a car run,air fuel,spark.Take any of these things out of the picture and the car won't run.If the car starts up and runs that means you have air.So the problem is spark or fuel.Take the car and run it until it stalls then check for spark or fuel pressure.It's a pain in the ass but it becomes a process of elimination.Also you said you had two mechanics check the ECU. How did they check it? The other thing is checking the coil pack.You just don't measure the OHM's without heating the unit up(just like under the hood)because at room temp it might check out fine.This has nothing to do with the headers on the engine.remember the cast iron manifold will get just as hot as the header, it just takes a little longer and it will stay warmer longer.(remember grandma had a cast iron wood stove in her house,once it was warm it stayed warm and continued to give off heat once the fire died down).Hate to say it go back and check everything again.Hope this helps and good luck to you.

well i guess i can only check everything else again. its becoming a huge pain but i have replaced everything and its all been tested and kicking my ass haah. thanks tho, appreciate the info.

 

[foxyspyder01gt]

vapor locking much that's a joke id say some thing along the lines of air or fuel problem leaning towards a fuel problem

 

[Viva]

Sounds like your car is overheating. Don't go by your stock gauges because any real mechanic will tell you they lie like a mofo. Do you have a infrared gun?

 

[208DSM]

Sounds like your car is overheating. Don't go by your stock gauges because any real mechanic will tell you they lie like a mofo. Do you have a infrared gun?

oh i didnt know that. but no i dont have a infrared gun why?

vapor locking much that's a joke id say some thing along the lines of air or fuel problem leaning towards a fuel problem

im thinking fuel too.but that's also why i kinda think my exhaust or o2 sensor could do it cause that's what sends reading to adjust my fuel charts and stuff ya know so if its gettin a faulty reading or something

 

[foxyspyder01gt]

i would check fuel presser and how old is your fuel filter? the overheating thing could be to. Check your radiator fluid not in the reserve but under the radiator cap and make sure it's full. I no mines was over heating big time cussed me the same problem i had to have it towed home come to find out the PO did not take care of it like he said now 7k later it's finely up and running or will be i pray.

 

[Jeff99GS]

A 3" exhaust on a 420a shouldn't make the car stall, but it will reduce back pressure and more than likely make your car SLOWER than it alreadys was.
Not to mention it sounds kinda lame like a mail man truck.

When I had a my GS i had the same problem with the car stalling randomly. It turned out i had a leak around my EGR valve. I took it all off and used a block off plate. That solved my problem.

Is there any Check engine Light on in the car?

 

[208DSM]

i would check fuel presser and how old is your fuel filter? the overheating thing could be to. Check your radiator fluid not in the reserve but under the radiator cap and make sure it's full. I no mines was over heating big time cussed me the same problem i had to have it towed home come to find out the PO did not take care of it like he said now 7k later it's finely up and running or will be i pray.

i did a fuel pressure check and it was good, also my fuel filter and fuel pump are both BRAND NEW like 100 miles on them both probably. and i checked my radiator and its good!

A 3" exhaust on a 420a shouldn't make the car stall, but it will reduce back pressure and more than likely make your car SLOWER than it alreadys was.
Not to mention it sounds kinda lame like a mail man truck.

When I had a my GS i had the same problem with the car stalling randomly. It turned out i had a leak around my EGR valve. I took it all off and used a block off plate. That solved my problem.

Is there any Check engine Light on in the car?

haha ya it sounds like shit, if i woulda known it was gunna sound like this i never woulda ever put it on my car . but yeah i checked my egr valve and it was all good?