Misfire and hunting with codes P0300, P0301, P0302, P0303 and P0304

Tiny
AARON1991
  • MEMBER
  • 2007 VAUXHALL ZAFIRA
  • 1.6L
  • 4 CYL
  • MANUAL
  • 103,000 MILES
The car is hunting and shaking taking time to build up speed. I have fit new coil pack, new spark plugs today. I fitted new coolant sensor and new o2 sensor still the same. Could you tell me why is bringing up p0300, p0301, p0302, p0303 and p0304 please?
Thursday, March 18th, 2021 AT 2:34 PM

1 Reply

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
The codes are telling you that you have misfires on all the cylinders. So we need to start with the basics and make sure we don't have vacuum leaks, we have proper fuel pressure, and the compression is okay. Here are guides that will help with each of these:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

https://www.2carpros.com/articles/how-to-test-engine-compression

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Let's run through all of this but I suspect you have an issue with the head being warped. has the engine overheated recently?
Was this
answer
helpful?
Yes
No
Friday, March 19th, 2021 AT 5:51 PM

Please login or register to post a reply.