Birty Dastards Jeep Club

Please login or register.

Login with username, password and session length
Advanced search  
Pages: [1]   Go Down

Author Topic: Severe misfire update  (Read 2393 times)

0 Members and 1 Guest are viewing this topic.

ikebaddog

  • Guest
Severe misfire update
« on: May 25, 2016, 06:29:55 AM »
If you remember some time ago whilst investigating a severe misfire , I disconnected the upstream lambda sensor, missfire disappeared, yesterday the old girl passed the MOT, with the sensor still disconnected!!! I had just simply forgotten about it, my point is, if it hasn't affected the emissions, what the hell, does it do???
Logged

Jonny Jeep

  • Regular Member
  • Forum Member
  • *
  • Guru: 11
  • Offline Offline
  • Posts: 1372
  • Vehicle: TJ 4.0 Sport
  • Year: 1997
Re: Severe misfire update
« Reply #1 on: May 25, 2016, 10:42:17 AM »
The upstream sensor does control emissions. If however it is disconnected the computer has to use it's programmed fuel tables with data from other sensors to set fuel trim.

It's possible it may run just slightly rich with no sensor, but when I had a bad one I didn't notice any change in MPG whilst waiting for a replacement NTK sensor from Rockauto. They don't seem to set codes very often with bad sensors so no check engine light normally which I think would be a fail these days.
Logged
Pages: [1]   Go Up
« previous next »
 
Powered by EzPortal