2002 Mitsubishi Lancer OZ Rally with automatic transmission. When shifting from park to reverse the transmission makes a clunking sound as if the mount was broken and transmission is moving. I just replaced the mounts engine and tranny, The fluid is at the correct level also. What could be causing this?

SOURCE: operating lancer automatic transmission

Have you Had the transmission fluid checked? It sounds as if the transmission is slipping in these gears which would point to a fault within the bands. To have a problem like this repaired could cost as little as $200 or as much as $1700 depending on how much needs to be done. Was the replacement a second hand transmission? If yes then did you have a warranty period with it? Let me know and I will get back to you as i am about to seek out a manual for this.

Cheers

SOURCE: i cant find the diagnostic

It will be on Either the Right or Left Side of the Steering Column Under the Dash. Also, Some of the OBD Outlets were Under the Hood Mounted Near the Firewall. Please Rate My Response! Thanks!

SOURCE: What kind of oil does a 2002 Mitsubishi Lancer OZ Rally need?

it takes 5 quarts of sae30 weight oil use either quaker state or valvoline this is better oil and doesn't sludge up the engine

SOURCE: tranny clunks when shifting gears

Your gears may be going. I would get it checked out.

SOURCE: 2002 mitsubishi lancer oz rally troubleshooting

Code p0420 is 'catalyst efficiency below threshold'.

This could be caused by a bad catalytic converter but before dumping a ton of money on that I would suspect the after-cat oxygen sensor is getting lazy and setting the code.

Have the O2 sensors checked and replace if needed before suspecting the catalytic converter.

Good luck.