Otay, I took ol' Bessy (my 97 Bonneville SE) up to AutoZone yesterday so they could run the codes on why my SES light is on. They said that the code was P0401, basically meaning a bad Exhaust Gas Regulator (EGR). I priced the part out at $143...Now at this point if the only thing its going to do is turn my SES light off then I don't see any reason in replacing it because latelly this car has been giving me pure hell and I want to get it fixed RIGHT ya know. It has been taking a LONG time to start, and I've checked fuel pressure, the regulator is ok, replaced the fuel filter ect. I did notice that after it is hot that sometimes when I start it from being parked for less then 30 minutes it runs like **** under 35mph, but if I mash the accelerater and get her sputtering up to speed she runs fine after that, but once I turn it back off its HELL to start it again, and it has backfired through my intake manifold twice now, causing the vacuum lines to come off of the throttle body. That being said makes me angry, cause the plenum is brand new and I REALLY can not afford to fix it again if it fails due to precombustion backfires. I just don't know what else to do anymore with it. It runs great on the highway though, I am just frustrated with it. Could the EGR be causing these problems?

97 Bonneville SE 251K
Replaced so far:
Coil packs (all three) @ 187,000
Water Pump @ 187,000
Radiator Hoses @ 242,000
Coolant Flushed @ 242,000
Thermostat @ 242,000
Upper Plenum & Lower Intake Manifold gaskets @ 242,000
Fuel Filter (twice) 242,000/251,000
Air Filter 242,000
PCV 242,000
Belt 251,000
Pressure sensor on plenum 242,000
Coolant Temp Sensor 242,000
Oil Pan Gasket 242,000
Spark plugs & wires @ 242,000
Plastic Elbow from lower intake to tensioner @ 242,000

Have you tried shaking the catalytic convertor back and forth? Try that and let us know if it rattles.

I haven't done that. Cat doesn't seem to be clogged to me, I can rev it up, stomp on it and she takes off like a shot gun, but at low speeds, or at start/stop conditions (usually in town doing errands) she does this. :?:

I feel like pulling a Shirley Q. Liquor on this thing and have Whatusie drive it through a Durry Queen :P

I shook and banged on the CAT it seems firm and doesn't rattle or anything

Sometimes removing and cleaning the EGR can fix it, but that'* true more for the 88-93 digital EGR valve than it is for the 94+ Linear unit. It'll cost you a gasket and a can of carb cleaner to try, which is significantly cheaper than an EGR valve.

Well I decided to take off the EGR valve today to see if it was carboned up. Suprissingly it wasn't and the little valve seemed to function when I had it off the car. I started the car without the EGR successfully after a couple of trys and blew all the carbon from the outlet for the EGR then put the EGR back on, and to my suprise it started up much better then before, but my check engine light is still on. Oh well. I'm probably just going to shell out the $160 when I get the chance and replace the EGR. I'm glad that I didn't mess up the gasket on this one, it came off fairly easy and went back on snugg and tight.

Autozone can clear the code for you. That will get your check engine light to go out. Clearing the code would be your best bet anyway since you're fix. It'* the one true way to determine if you really fixed it. No light appearing again = fixed! Then you won't have to shell out the money, either.

jessie, the check engine light may stay on for a while...if blowing out the carbon in the EGR valve was the fix, then the check engine light will go off after a while....I would drive it for a few days to see if the light goes out before purchasing a new valve.

Also, I know that disconnecting the negative battery cable for a period of time (I can't remember how long exactly..might be 30 minutes) can sometimes clear the light. You might want to search on "MIL" or "check and engine" to find out the time the battery needs to be disconnected.

Thanks ECHO SSEi. I'm happy that its starting up a hell of alot better. I just hope it stays this way till I could put some more money into it. After the last couple of months of shelling out a totally of $800 in repairs that I've done myself, it gets frustrating to know there is still problems with this car. I can't complain though being that its a GM with over 250,000 miles. Next thing to tackle is my ABS. I think the ABS computer is out on it cause it sometimes works and sometimes it doesnt, when it does the little computer next to the parking brake makes a buzzing noise then it stops. I think I can get a use one cheap at a pick & pull.

I hope the light clears for you...(I didn't think autozone would "clear" the code, but if they will... go for it)

And FWIW, I have the '97 FSM'*....and am always eager to help. Never even read the ABS section (very long), but I will help when I can.