How do you know if the engine computer is bad

Tune up,fuel filter,bad coils,air filter.

this is easy,, it can be 1 or 2 problems.

1: CAT is dead or weak, new cats can in fact hide a crappy engine.

2: bad engine. runs like junk and does not burn all its fuel.



any good shop can find this is minutes.

what I DO (no 5gas mach)

i check for (scan tool costing me $9 whole bucks) ask)

i check for closed loop status, idling

if ok then at 15mph and then 25mph , just racing motor in neutral.

if all 3 tests pass, im good.

if any fail, i fix that. bad fueling, bad spark or whatever.



if all 3 pass, its NEW CAT TIME



easy huh? a binary answer.

bad cat, bad motor. (or both)



when i say bad motor that means,every inch of the EFI/engine system.

every drop.

don't know - check enginre hoses by hand. clean PCV valve. run some gas additive for carb or fuel injection cleaner. regap spark plugs. drive higway for 15 minutes before next test. pay money to have shop run computer analysis. may show up bad stuff eg. distributor wires.

Hi, my first recommendation would be to take the plugs out and visually inspect each one and check to make sure they are properly gapped, if they look fouled at all i would replace them without hesitation. try throwing a set of NGK plugs in the car to fix the misfires. other than that you may want to look at the wires. good luck joe

Take the car to Autozone or similar dealer for free scan of the engine computer. Many things can cause similar problems. Good luck!

Are you sure your firing order is correct

it sounds like you have a bad catalytic converter or a bad miss fire . Is the check engine light on ? What year vehicle is it how many miles are on it ?

check spark plugs. and igntion coil.

Sounds like you may have gotten some debris in your exhaust pipe or something was clogging your muffler. Maybe the innerds of you Catalytic Coverter went and got stuck or the innerds of your muffler gave out. That would be the only few things I could think of to cause something like that.

Sincerely,

JC