Any ideas on this? When it is cleared it runs awesome, when the light comes back on it runs like crap..loss of power..hesitates from 3500-5000 rpms. Any clue?

This is on a 98 SE-R with a punched out converter and Stillen 4-1 header.

I looked it up...and it is yet another EVAP code????

I'm having the same DTC and the same symptoms. The ODBII scanner reads that the P1448 DTC is "Manufacturer Control. Auxiliary Emissions Control". Now what this means, I have no idea. I'm also throwing a P0440 Evap Emissions Control System Malfunction Code which may be related.

Perhaps someone can help us both out wih the provied info :confused:

dsblk93gt, I just went through the factory service manual. If you are having both the two DTC's I've indicated in my above post, then the EVAP canister vent control valve is probably not closing properly which can be caused by a few things which you'll have to check from the below list:

-EVAP canister vent control valve
-EVAP control system pressure sensor and the circuit
-Blocked rubber tube to EVAP canister vent control valve
-Water separator
-EVAP canister is saturated with water
-Vacuum cut valve

Now, I'm not too sure what the heck all the above means and sorry I couldn't provide more info, but this is what I got from the FSM. I personally will try to remove the vent control valve and see if anything looks wrong with it...if not, then I'll try to go down the list. I hope that helps.