How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Amedee Your Own Question
Amedee
Amedee, Jeep Technician
Category: Jeep
Satisfied Customers: 25084
Experience:  ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector
279429
Type Your Jeep Question Here...
Amedee is online now
A new question is answered every 9 seconds

I'm getting a 300 code OBE II after replacing engine,

Customer Question

I'm getting a 300 code OBE II after replacing engine, computer, plugs & coils (2), O2 sensors (4), and other sensors. Engine still reads a 300 code. If I start up and take off it seems to misfire than flatted out and runs almost normal that is when I get the code.
I have taken the Jeep to the dealer here in Korea all the say is I need a update and the jeep runs worst Please help
Submitted: 1 year ago.
Category: Jeep
Expert:  Amedee replied 1 year ago.

Hello and welcome! Thank you for requesting me! Can I start by getting your VIN?

Customer: replied 1 year ago.
1J4GR48K95C583248
Expert:  Amedee replied 1 year ago.
Thank you for the VIN!
Do you know what the engine vacuum is at when the engine is at idle?
Would you be willing to speak on the phone?
Customer: replied 1 year ago.
I'm in Korea. It's Sunday here My mechanic will be available Monday. I will have him check the vacuum at idle. is there anything else he should check while he has it. If you could send a list of things to check pls.
Expert:  Amedee replied 1 year ago.

Hello!

Thank you for the VIN! I would have your mechanic check engine vacuum. It is possible you have a sticky valve or a engine breathing issue causing the engine to misfire. The engine vacuum should have a solid 19 to 22 inches of vacuum. The vacuum gauge or needle should not fluctuate at all with the engine at idle. If so, this indicates a mechanical issue with the engine.

Also, check the camshaft position sensor and crankshaft position sensor. Check for a broken flex plate, loose or jumped timing chain, broken timing chain guides, cabroned up valves, chekc fuel pressure and plugged exhaust.

Amedee

Expert:  Amedee replied 1 year ago.
Hello!
It's Amedee from just answer.
I am just checking in to see how things are going and to see if you need any further assistance?
Let me know!
Amedee
Expert:  Amedee replied 1 year ago.
Hello!
It's Amedee from just answer.
I am just checking in to see how things are going and to see if you need any further assistance?
Let me know!
Amedee