Hi all, I recently bought a cheap 2.5 Indianapolis which needed a few bits doing to it. The problems left that have confused me are as follows:

1. Passengers on the back seats comment it sounds like the engines in the boot, when it's stationary there is no noise but once moving there's a noise which to be fair does sound like an engine in the boot. It's not the tyres or exhaust I was wondering if it could be the diff needing oil or a worn bearing?

2. Once the engine is warm it loses power if I try to accelerate over 3500 ram in 2,3,4 or 5 gear. (under load) I have already done the plugs, air and fuel filter. As well as trying injector cleaners. I've read quite a lot about the oxygen sensors, I had the car on the ramp tonight and can't find any sensors along the exhaust or pipe! Codes are P1000, P0037, P1646 and P1647 which I believe a couple of the relate to the Oxygen sensors. I am just a hobby day mechanic so I could just be being dense with these questions. Many thanks for any advice offered.