A few questions..

[crashfirepm53]

i just bought my wife a 2002 Galant 6 cylinder/auto. The car was used little in the last year and a few gremlins are popping. I installed new rotors and pads due to a pretty violent shake in the steering and pedal. It has smoothed it out but I feel like it may start to come back. Other than that the car drives incredibly good.

Any ideas about the vibration?

I have had a check engine light come on and scanned as a 421(I think) but is the rear o2 or the converter. I replaced the sensor and reset it but the code came back an hour later.
Replacing the Cat ain't an option so i'm thinking the Cat may fall off. Anyone know the exhaust pipe size?

Last question.... None of the lights on the Infinity stereo light up but the LCD does and the radio works great.
Any suggestions?

I didn't mean to double post this in the newbie folder.

[Rodriguez]

As far as the Stereo goes I never had the Infinity setup, so I cant help you there. The vibration can be a lot of things. Get the car in the air with a jack and take off the front wheels and check out all the front suspension components. Tie rods, ball joints, brake bracket bolts, ect. I'm no expert but I had some vibration under braking a long time ago and it was poorly maintained front suspension. There's a lot to be maintained in the front end of these cars.

Search is gonna be your go to tool. Search up pP0421 here if you haven't already, its a common problem with different solutions.