hello new uk scooby friends- I have a check engine light question, but before getting started will tell a bit about myself: I am thankful to find a group of fans- I am in rural eastern Oregon USA, I have an 02 WRX STI wagon, with 140K miles (love to drive this car!). have done all maintenance per factory recommendations- now retired and must perform as much maintenance myself as possible- I will appreciate any referral to any internet locations for advice, as well. I have a check engine light which reads PO 445, emission controls. Car is running fine (although I haven't run up past 5000 rpm). Other info: the car had an aftermarket scavenging exhaust which required a remap after I bought it in 04 (kept getting fouled plugs and misfire codes). has been running great for 5 yrs now. I want to learn as much as possible about the vehicle to keep it running for another 5 years.(too much fun!) Any ideas about what items/sensors I could check for this code would be appreciated- maybe 100K plus on the aftermarket exhaust means it's time for a change-? Thanks, and again I am glad to find "you all"- billystubob