Power Problem in 99 Subaru

subaru
acceleration
engines
outback

#1

I have a '99 Subaru Legacy/Outback, 5spd manual transmission. Besides being a 4 cylinder, it has no accelerating power. More worrisome is when driving, the engine feels like it’s “skipping” and it’ll lose some power for a second or two. This gets substantially worse when the AC is on. Could this be a problem in the fuel line or spark plugs? I bought the car from a used lot that had done most of the 100,000 mile work before selling it to me 8 months ago.


#2

I assume the previous work done on it included changing the timing belts which is the most important thing to do along with other things related to that. If that is correct it may be they didn’t get the cam timing exactly correct and it may be one or two teeth off on one or both belts. Doing a compression test should show if there is a problem with that kind of thing. You may also want to check the throttle position sensor and make sure it is working ok and doesn’t have a dead spot on it. Cleaning the MAF sensor and making sure the air filter is ok should be done along with changing the fuel filter. If doing those things doesn’t help then the exhaust system should be checked for excessive back pressure.


#3

It could be anything. Wheneven a performance problem exists and considering that spark plugs are usually the first thing examined, a compression test should be performed. One always weeds out the possibility of a weak engine first.
Scanning the car for codes is also a must. AutoZone will do this for you free.

A partially clogged catalytic converter can also cause this kind of problem. This can be verified with a vacuum gauge.
I hope the timing belt job was performed and if not you’re going to have to spring for that expense or take a huge gamble.


#4

Yes, the timing belt was changed. I also think there’s a crack or hole in the Y-pipe which is making the car louder when I drive. Could this also affect performance and power?


#5

Yes, a hole in the exhaust system can most definitely affect the performance of the car.
Get that fixed first, and see if your trouble is still occurring.

BC.