Hello, I have a high mileage (287K) '97 Rav4 that, due to the previous owner, uses oil, but OK since using Lucas additive.

Recently took it in to a non-toyota shop to get overdue timing belt, plugs, and plug cables done. Prior to this it used the standard 10l/100km (25mpg) gas. After the timing belt it immediately jumped to 13l/100km. Also seems to have lease power on highway but it drives smoothly.

For months prior to the belt change it had a stuck egr valve which had thrown an engine light but not affected gas consumption.

So, thus far, following the timing belt replacement, I have done the following:
1) took it back to the original shop to see...they found nothing although they didn't do much beyond take it for a test drive.
2) took it to a Toyota shop. They checked timing with a light (but not at the belt) and found it to be fine. They said that these results very likely meant that the timing belt had been done properly (is this true?).
3) took it to Toyota shop to fix egr valve / clear engine lights. Gas consumption still equally high
4) took it to Toyota to put in their recommended spark plugs, which they said could be the problem. Gas consumption still equally high.
5) reset the ECU by driving it to temperature, disconnecting the battery, letting it sit for an hour, reconnecting the battery, idling for 5 minutes and driving normally on highway for an hour. Gas consumption still equally high.

Anybody have any ideas what I should try next? Currently gas consumption is 25% higher than it has been for me in the past, which ads up at the pump. The original non-Toyota shop says it could also be the catalytic converter getting clogged up but to me it is just too big a coincidence that consumption jumped so abruptly right after getting the timing belt, etc. done.
Or is it possible that the engine is just at an end?

Thanks. Robertson.

 

Sounds like they got something adjusted wrong to me. TPS or ignition timing, I dont know very much about rav4's or their engines. But you should definitely not loose power and fuel milage.
Might want to consider another shop at this point.