car not picking up well HELP!!!!

[240sxvaj]

OK, so im on first gear punching my car and as soon as i hit about 4,000 RPM my motor just basically picks up faster but then i dont feel the power picking up like usual. mostly every gear it does that. it just recently happen about 3 to 4 days now. car is also all stock no mods at all, recently oil change about almost 800 to 1,500 miles and a brand new clutch about 1,500 to 2,500 miles ran on clutch. whats up? LMK! HELP! PLEASE! thanks

[Bwana]

Otherwise it runs normally? It could be a number of things. How long has it been since the car's had a tune up?

[240sxvaj]

well when i got the car it had brand new spark plug wires, ignition coil and distrubiter and thats about it. then about a month later i change my spark plugs to NGK plugs and now it done that. the sparks plug is about 6 to 7,000 miles on it and the wires about 8 to 9,000 (same with coil etc). i had the car for about 7 months now. everything ran fine until i replace my stock air box to a cone filter. but i wasnt useing any MAF adapter, so i was thinking its my MAF that must have been mess up. but not sure, when i change my filter my car ran stronger but the about 3 days later it became weaker then before. so now i just replace my stock box back on and it gave a little more power back but like my last post it had that problem. and the car runs fine, just a little weaker on the pick up then before. and the miles on the motor is 142,xxx. LMK if you know. thanks!

[Bwana]

What kind of filter were you using on it? It's possible that the MAF could have gotten oil on it and is now fouled. You can clean them carefully with electronic parts cleaner.

[240sxvaj]

it was just a regular one from autozone.......the filter was smaller then the MAF so it was inside of the MAF when i ran my car.......

[Bwana]

That filter could very easily have messed up your MAF. At least take it off and check it out, they're pretty fragile inside.

[240sxvaj]

how can i tell if the MAF is mess up? lmk thanks

[240sxvaj]

well, i figure out the problem, i had a exhaust leak. got it fix and now it picks up like usual. thanks for the help