'97 can't run on high RPM, no CEL?
 

I hope I get some help here because I tried everything I know.

I just got the PO400 code, cleaned the EGR valve and the EGR pipe and as soon as I started the car the check engine light went away (hurraaay!). I cleaned the throttle body pretty good as well. New gaskets for the valve and the TB.

The car has nice idle now and runs smooth on low RPM still won't rev in hight RPM! If I am on neutral (5 sp btw) it revs all the way like nothing. When I put it in gear and reach 3000 RPM it starts to stall really bad. I just gassed and gas mileage doesn't seem changed. With no CEL and clean throttle body I am really lost. Spark plugs are almost new iridiums + the car runs nice on low rpm.

Vacuum leak? I am no mechanic and did the EGR cleaning myself and I thought that I might have forgotten to put back some of the million hoses around the EGR valve. But as far as I can see everything is there. Do you know of any particular hose that might cause that so I can check it? Or anything else?

How about knock sensor or O2 sensor, should I replace those, hoping that it helps? I saw they both around$40 on ebay and ez to change..

Car has 90k miles and before those EGR problems used to pull like insane, I shocked all my friends with a 10yr old family sedan.. I want it back.. : (

OK this is weird, i just posted and refreshed, and the post got deleted, after i clearly saw it being saved

regardless, usually MAF problems dont let you rev past 2500 RPM, so this may be related, not sure...

BTW: usually you need at least 15 posts to make your own thread or you need to donate, i guess the dot org still has a lot of issues to resolve.

I believe you forgot to plug the MAF sensor back in....

umm, MAF? broken maf limits at about 2.5k rpms

it's plugged, but don't know if it's operating normally. Once I forgot to plug it in and the car wouldn't go even over 1500 RPM. Wondering how to check if its working.. It's ez to swap but expensive.. May be buy one from autozone and return it if it doesn't fix problem..

I got a knock sensor today and will swap it tomorrow. Will try to find a MAF sensor too just to test and wil post again. Tomorrow is all about my car so any ideas appreciated.

Actually, I'm pretty sure the ECU detects pretty well MAF malfunctions and I have no codes in the ECU.. I don't think it's MAF now..

Because he double-posted - http://forums.maxima.org/showthread.php?t=536144

Do you have a haynes manual? It's a relatively easy check with a multimeter. You can download the FSM, it'll have diag checks there.

The ECU technically should be able to identify a problem with any circuit it was programmed to check, but that's not always true. It could be responding lazily to airflow changes, rather than throwing out an incorrect or no value to the ECU.

When my TPS went bad...I couldn't go higher than 2800rpm in any gear. Maybe your TPS is going or is gone? Test it.

Tested the TPS. Shows 600 ohm tiwh no throttle and 4 000 ohm with WOT, which is what is should be.

Tried to replace the knock sensor but just cut my hands. Bough a variety of flexible expendable wrenches but when I reach it I can't turn it because of not enough space. How do u people do that? I read it's not hard on a 97. Do you remove something before you do that?