Need some advice about why my 99 max isn't like it used to be
 

Hey,

Lately my car feels like my parking brake is on all the time while driving mainly in the lower rpms. Also, the engine is louder at idle and when driving around expecially at WOT. I can hear the change in loudness because I have a CAI. I have about 60k miles on my car, so far i've changed the pcv vavle only. Now, I might have a bad exhaust gasket inbetween the muffler and the b-pipe. There's a slight drone to the sound of the engine at idle and while driving. But I don't think that I would hear this drone while I have my head stuck under the hood at idle.

thanks.

Well for one, @ 60,000 it's time to change the plugs. And it's very overdue for a fuel filter.

Oil and oil filter change?
Tranny fluid change?
Coolant change?

Changed coolant, changed oil. I have a 5spd and didn't change the fluid yet. Fuel filter also changed like 15k miles ago. Also, one week my gas mileage sucks and the next it's very good.

Thanks

You don't have to change your tranny fluid if you have a 5-spd. If you do, I'd put Redline MT90 in it.

Change your plugs, feul filter (the OEM one is 15K miles only) and maybe one of your rear calipers is actually stuck. It's somewhat common on 4th gens. It happened to me.

To see if your caliper is stuck, after having driven around for a while, stop the car and feel the temp of your wheels. My rear right one was quite a bit hotter than the rest.

Oh, and also, CAI filters get dirty way fast. You should get into the habit of checking it like every 5K miles. They pick up dirt like a mofo. If your CAI filter is a K&N, when you clean, even if it's a mild cleaning, make sure to re-oil it. I cleaned mine once without re-oiling. The car felt like it was gasping. I didn't re-oil b/c it was such a minor cleaning. The minor cleaning must've sucked all the oil out and made the K&N a choking hazard :gotme:

DW

5k is good advice, some people seem to think they can go 1,000,000 on the same filter, and that the dirt actually acts like a filter and performance improves as the filter gets dirtier. That's K&N BS. But I've had the opposite experience with the oil--too much oil will hurt mpg, especially when the temperature is below 20 degrees F. I once managed under 20 mpg on the highway when the temp was around 10 degrees F. I was really concerned--cleaned the K&N without reoiling, and the mpgs went back up to above 25. mpgs are poor in the winter but should still be reasonable. That oil is, well, a way to sell more K&N oil. Use it sparingly, a light coat.

Pull ECU codes and make sure you dont get 03 04 (knock sensor).

Thanks for your advice everybody :) My CAI is basically new. I will have to check my rear calipers out. I do have an O2 sensor code but that shouldn't make any difference, because it's been on for much longer than the current problem. Would new spark plugs make my engine quieter like it was before?? Actually, about two weeks ago I decided to check my spark plugs out, and to my surpise two of them were very loose(cyl 3/6). But my car was running better then ever with the loose plugs. After I went over the plugs with sand paper, put them back and tightend them the car became weaker like it is now.

Thanks.

Which O2 sensor ...
 

... is tripping? Could make a difference.