Background: 2004, 3.7 V6, 120k miles

Problem:
-Difficulty starting when engine is warm/hot (works great when cold *edit: now has a hard time starting when cold too)
-Can’t rev past 2500RPM
-Sputters and dies at times before warming up (doesn’t happen once engine is warmed up)
-Check Engine flashes at times (can’t pin down what causes it, comes and goes)

Any ideas? Crank sensor? Blocked cat?


Much appreciated.

 

Any codes?
A flashing check engine light usually indicates a misfire. Could be a coil pack, plug, etc.

 

Do the 3 key turn to check for codes.
Can be a few things ,coil misfire?
Be sure you got good spark an fuel pressure too.

 

The rev thing, is that in park/neutral or drive? A WOT takeoff from a dead stop would tell you if it's stopping at 2500 or not. Some PCMs (don't know if this is one that does) will limit RPMs in a non-drive gear. If revs are limited to 2500 in a drive gear, then you're likely in a limp-home mode due to a sensor issue. Any number of sensors failing can throw the ECM into a limp-home mode, including transmission sensor problems. A code reader will tell you the codes if the key turn thing won't. Cheap Bosch code readers can be had at Auto Zone. Finding out what the code is really needs to be your next step.