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Discussion Starter #1
So had a weird issue pop up. About four or five days ago, my car started randomly dying while driving. Started after I left work, turned a corner and started going and then it just shut off. Cranked over and turned back on when I turned the key (while still rolling). It did it one other time that night hours later. Checked for loose battery connections. Positive wire was a little loose, so I tightened that down really well. Hasn't done it since until just now. Driving home, died as I was coming to a stop sign.

The car also doesn't like to cold start now. It will turn over, sputter and die, then start on the second crank. Dying is just totally random. Can't figure it out for the life of me. Thoughts?
 

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might be the battery itself. You can get it checked at any auto parts, or wall-mart
 

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Could be a failing fuel pump. Upstream 02's can give hard starts and dying symptoms aswell.
 

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Discussion Starter #4
Upstream O2s could definitely be the answer. Since the tune, the car has been running richer. Might be getting gunked up? How can I test the fuel pump? I'll get the battery double checked as well!
 

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Upstream O2s could definitely be the answer. Since the tune, the car has been running richer. Might be getting gunked up? How can I test the fuel pump? I'll get the battery double checked as well!
well does the car completely die out of no where like its got no power, or does it stubble a little, rpms drop, and then die?
 

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Completely dies with no warning. After work today I took a look into the bay. The air filter I bought for my CAI (AEM Brute Force) has a hole in the tip of it for an IAT sensor, which is built into the MAF on 02+ vehicles. So I had a plug in it. Turns out that fell out at some point, so the intake has been sucking in a small amount of pollen/dust/wtfever else in the air for an undetermined amount of time. Pulled the entire intake apart, cleaned the hell out of the MAF and scrubbed down the inside of the intake pipe with a microfiber.

Car hasn't died since, and seems to start right up on cold starts now. I'm really hoping that the MAF was the issue there. Datalogged the car on a half hour drive and it didn't give me any issues at all.

Still believe the O2s *may* need replacing shortly, and/or the cats may be getting melted inside
 

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Completely dies with no warning. After work today I took a look into the bay. The air filter I bought for my CAI (AEM Brute Force) has a hole in the tip of it for an IAT sensor, which is built into the MAF on 02+ vehicles. So I had a plug in it. Turns out that fell out at some point, so the intake has been sucking in a small amount of pollen/dust/wtfever else in the air for an undetermined amount of time. Pulled the entire intake apart, cleaned the hell out of the MAF and scrubbed down the inside of the intake pipe with a microfiber.

Car hasn't died since, and seems to start right up on cold starts now. I'm really hoping that the MAF was the issue there. Datalogged the car on a half hour drive and it didn't give me any issues at all.

Still believe the O2s *may* need replacing shortly, and/or the cats may be getting melted inside
good man, and yeah having un-metered air in the engine will deff cause stalling.
 
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Hope everything works out for you. My car had that problem where it will just die randomly. I replaced the IAC, cleaned the MAF, new plugs and COPs and still did it. It ended up being the ignition module. Had that replace with also a new key and has not failed since.
 

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Completely dies with no warning. After work today I took a look into the bay. The air filter I bought for my CAI (AEM Brute Force) has a hole in the tip of it for an IAT sensor, which is built into the MAF on 02+ vehicles. So I had a plug in it. Turns out that fell out at some point, so the intake has been sucking in a small amount of pollen/dust/wtfever else in the air for an undetermined amount of time. Pulled the entire intake apart, cleaned the hell out of the MAF and scrubbed down the inside of the intake pipe with a microfiber.

Car hasn't died since, and seems to start right up on cold starts now. I'm really hoping that the MAF was the issue there. Datalogged the car on a half hour drive and it didn't give me any issues at all.

Still believe the O2s *may* need replacing shortly, and/or the cats may be getting melted inside
Hopefully you've found your culprit. These are never fun tasks to hunt down.
 

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Have almost the same issues car idles fine and will run fine for like 20 min a/c works fine also can come home let it sit for a couple min go to drive it again go down the street a/c stop blowing cold and car stolls out but will start back up no problem car has a rebuilt 4.6 with like 25 miles on it starter is new alternator is new battery is new thinking it might be my ccrm. Snake556 sorry for high jacking your thread
 

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If the MAF is messed up, theres a good change the throttle body is also fouled, carefully remove it, clean it all up real good, let dry (some say run it a lil wet? I wouldn't) and check out your idle then. I think theres a idle relearn for those with electronic throttle bodies, but google your year, I am not sure.
 

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Discussion Starter #12
Throttle body is brand new. Just installed less than 1000 KM ago. It looked fine when I took the intake apart to clean that. Car has been running great over the past few days, so I *think* cleaning the MAF fixed the issue. It's even been starting like normal again as well. Continuing to monitor it as well.

GT Rob, give your MAF a cleaning and check your IAC valve.
 

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I had the same exact thing happening on mine, and I just tightened my positive terminal on my battery and put some anti corrosive on it and I never had the problem again. The positive seemed tight, but apparently there wasn't a good connection. There were also times it would crank right up, and other times it wouldn't turn over at all. I'm sure you already checked it, just figured I'd throw it out there because the symptoms sound identical.
 

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Clean your IAC valve and battery terminals. That's good preventative maintenance. I had a terminal that cracked on the bottom half where there is a built in horizontal slit. It looked fine, but there was little contact to the post.

The problem might be fuel related if the problem still occurs. Or alternator if you have electrical symptoms.
 

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Car has been good over the past week now. Haven't had any issues at all after cleaning the MAF sensor. Battery posts are good, but I'll be giving them an even better cleaning sometime this week. Car has been starting right up, with no issues, no dying, no stuttering or anything. Hopefully all fixed up now! Really do need to yank the cats though. Car wants to spit flames, and I don't wanna melt them and block the exhaust haha
 

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Car has been good over the past week now. Haven't had any issues at all after cleaning the MAF sensor. Battery posts are good, but I'll be giving them an even better cleaning sometime this week. Car has been starting right up, with no issues, no dying, no stuttering or anything. Hopefully all fixed up now! Really do need to yank the cats though. Car wants to spit flames, and I don't wanna melt them and block the exhaust haha
Do high flow cats lead to clogs less often than standard/OEM cats?
 

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Do high flow cats lead to clogs less often than standard/OEM cats?
I've never had HFC but in theory you would think they would be more "free flowing" with less chance of debris clogging them up.
 
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