Hello, I recently purchased a 2003 Sequoia with over 300k. For the most part it still runs and drives excellently, but I recently noticed a power-loss / fuel delivery issue. The previous owner replaced the throttle and foot pedal sensors, as some forums suggest to cure similar symptoms, and "punched" the cats.
i get an o2 heat sensor code, likely as a result of the "high flow" cats, but it seems to be unrelated to this performance issue. The issue comes and goes independently of the CEL/resetting of DTC's.
What seems to happen is a sudden, intermittent loss of response from the gas pedal.
One thread I checked out indicated a possible sensitivity issue with the traction control system / VSC. Don't want to spend hours and hundreds of dollars trying to fix a fuel delivery issue, if it's a really a VSC chip issue.
Can I test for this (perhaps by temporarily swapping out my ECU)?
Is the VSC chip replaceable without swapping the entire ECU?

 

PS my "VSC OFF" and "TRACS OFF" warning lights are on, and seem to come on before the CEL after each reset