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Old 08-06-2015, 02:53 PM
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How do you reset the pcm

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  #21  
Old 03-04-2009, 12:14 PM
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Originally Posted by mcss8541
Hey Silver I know this is kinda off topic but I notice you're running a Flowmaster Super 40 and a Magna Flow Cat, how's that working out for you? That's what I'm in the market for. Currently I have the original cat and a 5 ft section of 3" straight pipe that has split duals out back.
I like it. I'm on my second Magnaflow, the first one broke up after only a year. I like the sound though.
 
  #22  
Old 03-04-2009, 12:32 PM
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Originally Posted by Silver_Dodge
It's complex when you start looking at open loop operations versus closed loop, but in a nut shell, speed density engines have no way to accurately measure the amount of incoming air into the cylinders. Speed density engines use a combination of readings from different sensors (namely o2) to give the PCM an idea of how much air is present. But it takes time because the algorithms used in the PCM require data collection over a period of time to so that it has confidence in the readings it is seeing. It is also not able to make changes that quickly either.
More modern Mass Air Flow (MAF/AFM) engines use a mass air sensor to give the computer that information real time, and it can therefore make changes to fuel and timing much quicker based on that information.
Cool thanks! Now can you answer my question about tyour exhaust system. 3rd time trying.
 
  #23  
Old 03-04-2009, 12:36 PM
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Your guy's PCM's take that long to calibrate themselves? Mine is usually set to go by the time I get to the end of my street. (1/16th of a mile)

It very well could be a California thing though. We have very very different emissions laws here, and the computer could be taking that into account.

I've never witnessed a rich situation with this truck though. If anything it runs lean from time to time.
 
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Old 03-04-2009, 12:36 PM
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Originally Posted by mcss8541
Cool thanks! Now can you answer my question about tyour exhaust system. 3rd time trying.
I thought I just did.
 

Last edited by Silver_Dodge; 03-04-2009 at 12:53 PM.
  #25  
Old 03-04-2009, 12:39 PM
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Originally Posted by Silver_Dodge
I like it. I'm on my second Magnaflow, the first one broke up after only a year. I like the sound though.
Just wanna add my 2 cents. I have the same setup, Magnaflow high flow cat and Flows. The difference, to me, is night and day. It's real responsive. I'd do it again.
 
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Old 03-04-2009, 01:42 PM
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Thanks Silver for the explanation. I just hate it each time when it has to go through the learning curve. I guess I'll just have to be a little more patient with it.
 
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Old 03-04-2009, 01:56 PM
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Originally Posted by Silver_Dodge
I thought I just did.
My bad Silver you did I didn't see it. Thanks!
 
  #28  
Old 03-04-2009, 01:57 PM
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Originally Posted by J415
Just wanna add my 2 cents. I have the same setup, Magnaflow high flow cat and Flows. The difference, to me, is night and day. It's real responsive. I'd do it again.
Want to pay for my new one? There is a difference, but I just dropped $140 total to put a highflow into my truck six months ago. That cat is not working so now I have to replace it with a "bigger" cat to keep with emission standards. I kinda disapointed with the forum a bit since so many people recommend them, but then at the same time they get a check engine light for it down the line. I didn't find out till the other day just how many there were that had this problem. Aim has found a bigger cat, but its still a thorn in my side knowing that I just dropped $140. Well the new cat costs around $130 local + I need pipe to run from the cat to the muffler since the stock pipe is very fragile. Add in the o2 bung, install, etc.. Looking at $200 minimum I fear. I should have just left the perfectly good stock cat still in the truck. Lesson Learned!
 
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Old 03-04-2009, 01:57 PM
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Originally Posted by J415
Just wanna add my 2 cents. I have the same setup, Magnaflow high flow cat and Flows. The difference, to me, is night and day. It's real responsive. I'd do it again.
Thanks! Well Look like that's what I'll be ordering.
 
  #30  
Old 03-04-2009, 02:05 PM
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Originally Posted by pcfixerpro
Want to pay for my new one? There is a difference, but I just dropped $140 total to put a highflow into my truck six months ago. That cat is not working so now I have to replace it with a "bigger" cat to keep with emission standards. I kinda disapointed with the forum a bit since so many people recommend them, but then at the same time they get a check engine light for it down the line. I didn't find out till the other day just how many there were that had this problem. Aim has found a bigger cat, but its still a thorn in my side knowing that I just dropped $140. Well the new cat costs around $130 local + I need pipe to run from the cat to the muffler since the stock pipe is very fragile. Add in the o2 bung, install, etc.. Looking at $200 minimum I fear. I should have just left the perfectly good stock cat still in the truck. Lesson Learned!
PC there's a quicker and cheaper fix. Check this out go to the autoparts store and buy a spark plug non fouler they are 18mm which is the exact thread of your O2's. Put the lower end in a vise and snug it down. Take a hacksaw or a cutting tool and cut off the top octagon ( stop sign looking, like you could put a socket on it )portion off and toss the rest. Take drill and drill a hole in the location you are installing the O2 ( measure the correct location) weld that on and you have an O2 bung. I just did mine last week after replacing the straight pipe than ran between the cat and the tail pipes. Total cost $7 which included the welding. I do have a question what size is the cat AIM was referring to? Name of it?
 


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