P0420 code for 2002 Subaru Legacy GT AWD 2.5L?

po420 low catalyst efficiency below threshold bank one. the cat is not condemned with that code but the factors that make it work should be tested, a vacuum leak in the back that feeeds that side should be looked into. if the cat does not see a rich lean rich lean condition in the engine, the cat will not work as desired. it has to see oxygen on one cycle to absorb and be able to distribute that o2 on the next cycle.

2002 Subaru Legacy Gt

I'd take it into a Subaru dealership and have them take a seem at it, however first assess these things... -Tire strain -If its a guide ensure your not going to excessive along with your RPMs -be certain that the air filters are good enough -verify to peer if its just the gauge performing bizarre, i have a ninety nine Subaru Impreza Outback that gets 27 mpg but the gauge for the fuel is by and large a little quick and tells me i'm empty when i have 1 / 4 of a tank left. -also, investigate your brakes and be certain they aren't adjusted incorrectly ensuing within the brakes consistently being on, which isn't just right! Excellent success!

PLease so yourself a HUGE favor!!! TAke $20 to the local quicky lube and have them clean out your THROTTLE BODY and IDLE AIR CONTROL VALVE to SHOWROOM conditions. The IAC fine tuens the AIR portion of your induction system. A dirty IAC and THROTTLE BODY will CUASE a bad air/fuel mixture, and trigger the O2 sensors and ever heats you describe here. MOSt cars NEVER really need new converters and only a few requrie new O2 sensors really if the AIR/FUEL mix is CORRECT! YOUr THROTTLE BODY and IAC should ALWAYS be SHOWROOM perfect and hospital floor CLEAN to do there work best. GOOD LUCK!! CHances are YOU did not need new O@ senosrs EITHER Just BETTER fuel mixture. CHECK your TIMING BELT as well. If it is going off base and getting loose, so will your air/fuel mixture. GOOD LUCK!!!