Hi there folks! 

Got CEL codes 42 and 33 pulling on my good old 1993 legacy. 

 

In reference to the 33, the speedometer stopped functioning. I have pulled the transmission side of the cable and the tab is present and appears to spin well. Wondering if there is any other troubleshooting I should do before pulling the gauge cluster out of the dash to see if that side still spins. If the cable is not the issue do I need to replace the cluster or is there a way to repair the speedo itself? The salvage yards around me are pretty sparse for the older models. If it is the cable it appears that replacements are no longer avaliable. What would yall advise I do at that point?

 

In reference to code 42 the engine started to idle significantly higher then usual recently. Then started throwing 42. The odd part is when I run the car in test mode (green connectors under the dash attached) it only shows the codes as running codes and not in memory and the car idles perfectly in that mode. I suspect the IAC has gone bad, and I do have a replacement that I can put in there that i know is good. But I wanted to see if there was any specific troubleshooting steps I should take before swapping it out?

 

For reference I installed purchased and installed a rebuild just over 800 miles ago and the car has been running very well up until the last 2 days. It did, however, really struggle to pass colorado emissions standards. Ended up adding an additional cat to get it to pass. At that point the high idle was not present, neither was code 42 or 33 and the speedo was functioning just fine. 

 

Please forgive me in advance as I am limited thus far in my knowledge and want to learn more. I love my subarus and I love working on them. I've got a fair bit of knowledge, but I would not consider myself an expert by any means. Thanks in advance for your guidance.

Sping the speedo cable at the transmission end and see if the speedometer goes.  Lots of times they will become disconnected behind the dash.  It just plugs in.

IAC cleaning is always a good start.

As for spinning the speedo would you suggest just putting a drill to it or something similar? The vehicle needs to be on when I do this correct? 

IAC was cleaned very thoroughly before I installed the new engine, but I'll pop it off and take a look. Can't really hurt to try. 

Thanks so much for your advice!

 

It's a direct mechanical drive.  I'd spin it by hand first to make sure it's free.  Have someone in the car to look and listen.  You may have pulled it loose from the back of the dash when you did the engine change.  It's tight, but if you drop the kick panel you can worm your hand up to the back of the cluster and push the spedo cable in to seat it.