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Is the check engine light on?
Are there any fault codes stored?
Can you duplicate this concern during a power brake test?
Let me know.
Have you cleared the codes and test drove to see which ones come back?
You have 3 different areas of faults according to your codes.
Inspect the IAT/MAF (intake air temp sensor/mass air flow sensor) connector for poor connection or damage. This is related to code P0113
P0455, P2404, P0442 are all related to an EVAP emissions fault.
P0421 is related to a faulty CAT CONV.
U0073 is a communication fault between modules and is usually caused by a low battery.
None of these codes are for a misfire. Clear the codes and test drive.
Let me know your results.
Have you checked or replace the fuel filter recently?
Pinch off the purge solenoid hose that attaches to the engine. Test drive for change.
Do you have a scan tool that reads live data or just a code reader?
Disconnect the battery and touch the cable ends together for 30 seconds. Clean as needed and reconnect. This will reset the module.
Test drive and let me know which codes come back.
Ignore the fuel filter, I was thinking about a different car.
You scan tool reply is ??? You do NOT own a scan tool, but it does read live data?? What reads live data and hoe did you get these fault code read??
We can only communicate through the JA site. Sorry.
Also try and clean the MAF sensor and test drive. Try and test drive with the MAF connector disconnect. Note any change.
Here is another diag.
I will check back for your reply in the morning.
Sorry for the delay.
Happy New Year.
The purge valve is supposed to be normally closed. It opened during cruise speeds.
I just wanted you to pinch off the hose for the purge solenoid where it connects to the engine. If you removed it, there should have been a vacuum leak, unless you plugged the leak.
With your scan tool, let me know what the short and long fuel trims are, with the engine running, warm at idle.
Did you perform the other test also and what were your results with the MAF??
Were you able to get the fuel trims for me??
Does the stuttering feel like a misfire?
Do you only get the stuttering on acceleration??
Does the engine idle smooth??
Can you duplicate the stuttering by doing a power brake test??
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Have you resolved your concern??
Here is a answer that you can accept.
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