Low rpm problem

hey, my 2g gs shudders a lot under load when its under 3000 rpm. i know all the easy stuff, like the plug wires are all on, etc. - but the plugs look good, there's no visible leak in the intake system, and the vacuum line isn't off or anything. does anyone know how to check to see if my mass flow sensor or throttle position sensor is working? those are two of my main diagnosis', but if anybody has any other ideas, please let me know, i love my dsm :) i hate to see it not run right
thanks

2g non turbos don't have a MAS they use MAP as for shuddering be more specific.

look up a couple threads, i posted several suggestions for your type of question.

the shuddering only happens when the car is under 3000rpm. it happens in any gear with full throttle or any throttle more than that used for slowly accelerating..... that probably didn't make sense, but what im saying is i can baby it up past 3 grand and it runs fine, at speed it runs fine. it feels almost like the fuel is cutting out. i'm not an experienced mechanic, but i've got plenty of time under the car, and it almost seems like its running rich. the injectors are not dirty, so i figured besides from an air leak, it must be electronic. your thoughts?

What plugs are in the car? What are they gapped at?

the plugs are stock, i haven't changed them since i bought the car this summer, the only time i had them out is when i checked the compression, and they didn't look fouled or anything then, that was a few weeks before this started happening.....

I would go and change the plugs.. something like this happen to me and it turned out to be the plugs. My plugs looked just fine also. I would go get NGK BRP5ES, should cost about $7.

Thanks, turns out there was a vacuum hose that was leaking and my plugs were running way lean and were really white. i replaced both, and i plugged up the egr valve, and the problem's gone! thanks for the help
-j

i like the bosch platnum,i know ash does not think it is a good conductor,but he is wrong
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