acemodder

Hi

I have the following error codes:-

P0420 - Catalyst System Efficiency Below Threshold Bank 1

P0340 SUBARU - Camshaft Position Sensor 'A' Circuit Signal Fault Bank 1 Or Single Sensor

P0031 SUBARU - HO2S11 Heater Control Circuit Low

The first error is due to me fitting an exhaust with no CAT on at all. However these other 2 codes concern me! The car runs fine though???? Is there a big problem, or is it just two dodgy sensors.

acemodder

Nobody have any ideas?

Don Clark

P0031 refers to the A/F (Lambda) sensor in the manifold just before the up pipe.
Heater circuit is the usual failure mode although if you 've been playing with the exhaust you may find some damaged wiring to it.

http://www.obd-codes.com/p0031

P0340 diagnostics

acemodder

Would the sensors results be out due to lack of cat then?



And would this cause any issues, do I need to replace the wiring etc?

Don Clark

The code suggests the heater circuit for the A/F (Air/Fuel)sensor has died, either the element in the sensor has gone or you have damaged sensor wiring near the up pipe. Nothing to do with Cats.

Car will run OK but your MPG may suffer........

You need to check the wiring, if no damage then a new sensor.
Some people refer to this as an O2 sensor.........
For a forester but exactly the same on newage imprezas......

http://www.scoobymods.com/showthread...nsor-9398.html

acemodder

The first code is due to not having a CAT at all (naughty me)

The third code is the one that concerns me. I have unplugged the cable and the wire is giving a live feed, so the sensor is fubar. However I cannot see where the sensor actually is?? Can anyone tell me?

This is the plug where I tested for a live feed (is this right?)

rob84

iTrader: (5)

Unplug the grey wire, Its bolted to the coilpack on cylinder 3 then follow the wire down to the corner of the exhaust manifold its in the collector pipe pre up-pipe

Don Clark

Exactly the same procedure for a Newage Impreza


http://www.scoobymods.com/showthread...nsor-9398.html

acemodder

Thanks guys. New sensor ordered from Euro Car Parts

Don Clark

Can be a bugger to get out if it hasn't been changed before, so some pre-soaking in release oil may be advised and a good well fitting socket/ring spanner/oxygen sensor socket required........

rob84

iTrader: (5)

Good luck with an aftermarket sensor. they tend to throw a fault up for slow response