Start then stall

[frentraken]

Hey all, I bought this 1997 sunfire (Think it's the SE, nd I know it's got the 2.4)
last fall and it's been good to me since. Except now that we're getting to summer months it seems whenever it's over 25 degrees(That's in C as I'm Canadian) out It will start and then immediately stall throwing up a p0401 code if I scan it. ON cooler days it's not a problem, and once I get it in running it will stay running fine.

So stuff I've tried was seafoaming the intake to clean it all out. I've tested the IAC and cleaned it out, and pulled and cleaned the EGR valve itself aswell as the tubes feeding it, though I only got about 10 inches in with the snake I was using not sure how deep those run.

Other notes being the fuel pump does activate and prime when you turn the key, but I haven't tested pressure on it. Oils been changed 3 times since I've owned it, and I've run Lucas Oil stabilizer, and fuel additives for giggles too.

I'm at my whits end on this thing, I wasn't very well versed in any of this going in, and with what I've learned I don't see any other options that would be this intermittent.

 

[melsg5]

why havent you replaced the egr? It also appears that the map sensor can effect the EGR.

http://www.obd-codes.com/p0401

http://repairpal.com/OBD-II-Code-P0401

 

[frentraken]

I've not because it's one of the 5 wire Electrics that cost 300 and everything I've read say these are rarely at fault themselves, and when they do go it's an all out fail. Haven't done anything with the MAP since repair pal seems to be the only one that really points to it though it, and the coolant sensors were next up for checking but I've been kinda caught on the EGR tubes being plugged.

 

[melsg5]

wow, I see Napa has them for $180 to $220, crazy price. This link has a number of tests for the 2.4 which may help

http://easyautodiagnostics.com/gm/2.4L/index-of-articles-1