Jump to content
Ultimate Subaru Message Board

Recommended Posts

I just replaced the O2 sensor in my 90 legacy wagon and it is running pretty good but now it is giving me the 42 code. WTF! What is it and what does it do? How do I fix it? What will it do or not do untill I can fix it?

 

Thanks everyone for looking. I appreciate everyones input. Even if it is to say I am SOL!

 

What does the Subaru God (Josh) have to say?

Link to comment
Share on other sites

Here's my yet-to-fail fix for that code.

 

Swap throttle bodies. Pull one from a junkyard. I have swapped throttle bodies on my car to have one that still has its factory settings (I played with stopscrews when I was younger :-\ ). Then I did the same with a coworker's 92 Legacy who had the same code. Problem fixed.

 

The idle switch is built into the TPS, which is on the passenger side of the throttle body. The TPS is set from the factory in a certain position, you can see the white marks on the screws. It's best not to mess with that, so if you just swap the whole thing, you won't have that problem.

Link to comment
Share on other sites

Test the idle switch in the TPS.

 

Follow this procedure

http://www.main.experiencetherave.com:8080/subaru_manual_scans/FSM_Scans/TPS_testing3.jpg

 

Here's the preceeding info, which tells you which pins are which

http://www.main.experiencetherave.com:8080/subaru_manual_scans/FSM_Scans/TPS_testing1.jpg

http://www.main.experiencetherave.com:8080/subaru_manual_scans/FSM_Scans/TPS_testing2.jpg

 

If it's out of spec, adjust it so the readings are in spec, clear the codes, and see if you still get the code.

Link to comment
Share on other sites

Even if those tests check out, you still might try subyluvr2212's suggestion. In my experience, the idle switch code is sometimes thrown when there's an inappropriate load on the TPS power supply, and that can be caused by something weird in the TPS.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...