My 94 ssei servic engine light went on at the top of Mt. Washington 6,400 ft.? For the next year or so the boost gauge wouldn't go past 0 and it was slow. A year later we went up the mountain again and when we came down it worked for a half hour. It also works for a minute or two everyday when I leave work so I manage to spin the wheels a little. One snap on comp. said code 640 Quad driver. A second, better comp. said another code, 4 digits but I can't find them right now. Any ideas? Thanks.

Change your boost control solonoid (wastegate). It'* about 30 bucks if memory serves. I'm betting you get really shitty mileage, too.

Follow Will on this. I had the problem with the 640 code for almost a yr. C/e light and all. I tried a new PCM but turned out it was the boost solenoid but if you call it that the dealer won't know what u mean. The dealer calls it a valve kit (pn#1235-3309. Price is like Will said abt $30.

Okay, please tell me more about this boost control solenoid or valve kit as dealerships call it. My boost only goes up to about 9 psi but when i first did the smaller pulley conversion, it would get up to about 12 psi. I also have shitty mileage. I am only getting about 18 highway ugh. Do you think I need that valve kit from the delership. Also, where is the boost control solenoid? Thanks

make sure your MAP sensor is pluged in fully, it is what monitors boost, mine came loose, broken clip on the plug, and my boost would constantly read 0, i popped the hood and it was loose, snugged it up and wella. just a idea.

I was just wondering if a 1995 SE SC has a MAP sensor. It has no boost gauge.

Thanks,

bigt

yeah, your car has a MAP sensor, should be a little rectangular black box just inbehind the SC. it'* roughly 3 inches by 1 1/2 inches big. it will have a 3 wire connector and a vacume line going to it. hope this helps.

can anyone please tell me where the boost control solenoid is? I want to know if I should replace it and how easy/hard it will be. I am willing to buy a replacement to see if it helps out on boost and mileage. Thanks