Codes, P0304 and P0308

2004 JEEP GRAND CHEROKEE
119,800 MILES • 4.7L • V8 • 4WD • AUTOMATIC
Avatar
BMCCLA2
  • MEMBER
  • 1 POST
Codes have been coming up for the longest on my vehicle. So much money spent and still no one has been able to find what's wrong. Now the codes, P0304 and P0308 are showing. I've noticed a burning smell, the vehicle is running rough, loss of power, it hesitates and even shakes and cuts off at times. What could it be?
May 4, 2019 at 5:59 AM
Advertisement
Avatar
KASEKENNY
  • CERTIFIED EXPERT
  • 18,907 POSTS
Hi BMCCLA2

So you have misfires on 4 and 8. I assume you have done plugs, coils, and injectors?

Are they always the same cylinders or have they been moving around?

Can you give me a detail history about what has been replaced so I don't recommend something the same thing?

Have you done a compression check on all 8 cylinders? Can you send me those numbers?

Have you checked fuel pressure? If so, what was it while missing?

Also, what are the short term and long term fuel trims on each side (If you have access to a scan tool)?

Let me know this info and we can go from there. I am very familiar with this engine so I am sure we will find it. Thanks
May 5, 2019 at 6:08 PM