95 Astro 4.3 W 2wd codes went away

[usafret]

Hello all, I read all the posts on the SES for this van. Here goes. Fuel pump and filter r&r about 4 mo. ago. SES light came on early winter went to autozone about a week ago and it coded 12/13, r&r the o2 sensor, SES still on back to autozone code 12/32, map sensor r&r. The light was still on but running "ok". Went around with carb cleaner looking for a vacum leak,couldn't find one. About a day later going home van stalls out, crossways in an intersection, get it started and next 5 miles home was throw it in neutral/ rev engine to get home (at Every stop and slow-down) was thinking fuel then realized if I slowed with-out the brakes (vacum) it would stay running. Van died at the end of the driveway, When I backed it in expected it to die again and even with the brake on it now seemed fine ,SES still on. Throughout this whole thing the light only came on a while after the van was running (warmed up). Got up the next day, looked at vacum line to air box pulled it off and checked for tight fit,looked at the elec. connector in the air tube etc., started around the tons of stop signs in the area then proceeded out to the freeway, 15 mile round trip, NO stalling and NO SES light. Ran it up for the E-check,passed quickly. Now,every thing I replaced, and every time I pulled a line to check it, I would pull the battery cables and turn the key a few times to re-set the computer. The reason for this post is it's like waiting for the other shoe to fall, any Ideas on why it acted up so bad the one day and what to check? I had not pulled the battery cables after the awful ride home. Thanks

[Leeann94astro]

Code 32 is EGR, not MAP.

Pull and clean your EGR valve, paying special attention to where the pintle seats on the base. Put it back on with a screened gasket to avoid future issues with carbon chunks, too.

Out of curiosity, has your gas mileage decreased recently?

[usafret]

Yes gas mileage has been lower, however was letting it warm-up a lot more this winter due to the severe cold spell. Also, looking at Autozones book, code 32 for obd1 was map sensor, code 32 was listed in thier book as egr for another vehicle(s). So since I did nothing with the egr valve are you assuming a carbon chunk gave me (the van) that fit the one night? Thanks

[Leeann94astro]

It's possible. Sticking the pintle all the way open would allow a lot more air in and make the computer (and O2 sensor) think the van was running lean, so it'd pump more fuel in. A dirty IAC, a faulty O2 sensor, a fuel leak under the plenum, a stuck-open EGR pintle (carbon buildup) - all these can lead to a code 32.

The easiest to do first is pull and clean the IAC pintle. Old_Master has a post in here somewhere about how to take one apart, clean it thoroughly, lubricate it and put it back together. For the EGR, if you have AC, you will need one 10mm wrench (ratcheting is easier if you have it) and one 10mm deep socket with at least 9" of extensions (and I stick a little piece of paper towel in the socket 'cause that holds the nut when it comes off so you don't drop it).

[usafret]

Thanks for the suggestions. As I'm not "automotively inclined" I am off in search of IAC pintle post. I would also assume your w/ac is telling me the EGR is behind the ac compressor? Yes,unfortunately, I must rely heavily on autozones' help menues. Mechanicaly inclined just automotively ignorant. Thanks

[Leeann94astro]

More right behind the serpentine belt tensioner. You'll have to remove the air filter box and tube - be careful to detach the electrical connector to the intake air sensor on the underside of the tube, right before the throttle body.