Jump to content

Mod

ryan255

By ryan255
in Ask A GM Technician

Recommended Posts

ryan255 Enthusiast

ryan255

Posted
Posted

I have an 2004 GMC Envoy with 4.2L engine, and I buy a mod:

 

This mod will modify my stock ECU with a Timing Advance Resistor. This resistor connects to the car's ECU by replacing the Intake Airflow Temperature (IAT) Sensor. When the resistor is installed the ECU will read that the air coming in through the intake is cold air. In other words, this will modify the air/fuel mixture, producing more power and advancing timing 1 to 2 degrees.

 

The instructions are:

 

1.Locate the IAT Sensor, has to wires connected to it.

 

2. Unplug the IAT Sensor from the wiring harness.

 

3. Take each lead of the resistor and put it into each lead of the wiring harness plug. Put it tape.

 

My questions are:

 

1. I locate the IAT Sensor, but I cannot unplug the wires connected to the IAT Sensor. How I unplug that?

 

2. The mod will damage my engine or something?

 

3. Can I use the mod everyday?

blue2kzr2 Enthusiast

blue2kzr2

Posted
Posted

I wouldn't bother with that mod. All it does is trick the ECM into thinking there's cooler air coming in so it'll dump more gas in the engine. You'll get less MPG from the whole deal...

MrQuadrasteer Senior Enthusiast

MrQuadrasteer

Posted
Posted

And probably not pass inspection, foul your plugs and O2 sensors, leave your exhaust pipe black...

 

Lemme guess- you bought this on eBay for $25 ?? Guarantees 15 or more hp ?!!?

100R1 Enthusiast

100R1

Posted
Posted

I would not do this mod if it was my 2004 trailblazer (or any newer vehicle OBDII controlled)

 

you are going to hack into your wiring harness at the MAF to get to the IAT. what will this do to your warranty if you have any problems ?

 

You have O2 sensors pre & after cats, this will make the mod less efective than on the older OBDI vehicles. Plus you will molre than likely start to throw codes.

 

I built several IAT sensor mod boxes based on SpeedTweekes design for older (pre 1996) Jeep 4.0 engines. on these engines it was effective. parts were resistor, reistat, dual position switch, plastic box, and wire. cost from radio shack about $ 4.00 total

 

Since the IAT sensor on a 4.0 Jeep engine is on the intake manifold and only has a 2 wire plug I found matching male & female plugs to hook up my SpeedTweekes IAT adjustable mod. No hacking and easy to pull if I ever needed to go to the dealer (never had to)

 

The with the adjustable IAT mod you could trick the Computer to think that the outside ambient air temperature was much colder than it actually was and the computer would enrichen the fuel mixture and add timing advance.

 

on the 4.0 jeep motor they were put on a dyno and the power increase was 10 - 12 HP to the rear wheels.

 

The best way to decribe the performance gain is that it felt like you were running in the winter time even though it was summer time (well at least for us in florida) less humidity and less heat your vehicle picks up a little more power.

 

This was on a OBDI (pre 1996) engine current engines running OBDII will not see the same increase.

 

Not worth the time , effort and risk.

 

Invest into a Tuned PCM you will not be sorry going this route. Look in the Full size Forum there are post about low cost custom tuned PCM's.

asilverblazer Senior Enthusiast

asilverblazer

Posted
Posted

Please stop shopping for the sake of your car. If you want to spend money on worthless crap please make checks payable to Andrew Doug...

 

No don't put this stuff on your truck. And avoid EBAY at all costs. :chevy:

USA1Fan Enthusiast

USA1Fan

Posted
Posted
And avoid EBAY at all costs.  :loser:

 

 

 

Hey! EBAY is a good site to get deals on the stuff you want. Just make sure you go there looking for specific things and don't get taken in by some of the stuff you'll run into. I got good prices on both my steps and my tonneau through EBAY. :chevy:

MrQuadrasteer Senior Enthusiast

MrQuadrasteer

Posted
Posted

Yeah, I 2nd USA's comment. eBay kicks butt, BUT you have to do your research, and avoid the too-good-to-be-true bs that folks sell on there.

 

Like $25 chips, bs air-flow devices, eletric superchargers :chevy: and the like.

 

I've made off like a bandit with stuff I've gotten off eBay :loser:

 

 

Ryan, if you'd like to pm me, I'd be happy to talk to you off-line about decent ways to improve your performance and economy without wasting your money.

 

W/out a doubt, a custom tune is your best bang-for-the-buck mod you can do.

 

Trust me, amongst all the members here, I doubt there's anything that hasn't been tried yet, so listen to those with experience :D

jamashke Enthusiast

jamashke

Posted
Posted

Highjack......

 

Turbonator? So GM puts on a filter right before the MAF to "smooth" out the air. So why introduce turbulance to the air flow? Although GM does a good job of that with the OEM air tube. Oh well. Just give me some good ole beans and watch my mpg's go up by 50%.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Deadwood
      10L1000 anyone with High Mileage ? I hate Damocles....

      By Deadwood · Posted

      New member here, very long time occasional guest. Saw this thread, thought it would be a good time to contribute someting. It is only my experience and not a claim that everyone will have the same.   I bought my '20 3500 L5P new and have put 99.9% (literally) of it's current ~400k miles on it myself, with over 50% of that towing loads between 4k to 15k, and to me this truck has been nothing short of amazing. For the first 235k I had zero issues, and from there until 321k I replaced a NOx sensor, two failing glow plugs, and three of the notorious injector connectors. I believe this truck is in part, a testament to good luck, but also good care and following a decent maintenance schedule (I also keep meticulous records.) As a result, it looks as good as a well cared for 70k rig, up and down, inside and out.   At some point before that 321k mile mark I began to get a little spooked about the 10L1000, especially the valve body. Word of mouth about potential issues prompted me to jump on the net to sift through all the noise and determine what all the fuss was about. I routinely take long trips, coast-to-coast and points in between, so roadside breakdowns can be '...a thousand miles from nowhere' and a bit of a challenge, and though I had no issues, my guard was up and activated.   And then I stumbled across a chance to salvage some parts off a new 2025 that had been wrecked in transport. I grabbed a few wear items (alternator, pulleys, etc.) and on a whim asked what the ten speeder would cost me. It was cheap...really cheap. I knew some changes had been made in the '24+ version 10L and were supposedly not compatible, but I called service/parts at my local Chevy dealer and asked why and they didn't know. A call to a well known aftermarket transmission outfit revealed it was very likely it would be fine, but to them not 100% sure.   Because it was cheap (really cheap) and I was spooked, I took the chance. Had it installed by a local shop and it worked like a champ, shifted just like the original. At it's first service at 37k, I had the shop put in a Next Gen valve body kit, which after some initial hiccups and rough shifts, smoothed out though with somewhat firmer shifting.   All that said, I have a very serious concern about my newer transmission as just two weeks ago it suddenly began to exhibit a strong reluctance to engage forward or reverse. It was a bit past due anyway so I took it in for service. The reason it was sticking was due to 'glitter' in the fluid clogging the filter...not good folks, often indicates a converter giving out. We ended up going ahead with the new filter and fluid, first to see if it would move and shift, and then if so buy me a little time. It did, and I've driven it over a thousand miles and it is shifting smooth, no noises or slipping. Regardless, it looks like a third gearbox is in my future so I can resume taking long trips with some confidence. In the very short term, my curiosity will have me examining the fluid to check how much glitter has reappeared.   An earlier poster had alleged, in the context of 10L100 failures, that it is another example of how we seasoned citizens somehow descend into hysteria, lose control of our senses, and react irrationally after brief encounters with the idiocy of the internet infosphere. Let me say (and I have used and abused said internet since it's infancy) there is no segment of the populace that has a corner on over-reaction to digital garbage. Just as my offering of experience in this arena is purely anecdotal and should not be considered gospel or all-encompassing, I believe it is still worthwhile information to consider, along with other relevant anecdotal experiences about things like complex transmissions, especially when balanced with other sources.   So to answer the original question, yes I got high miles out of my first 10L, trouble free for 321,000. Now I really wonder how much longer it would have went. Did I 'overreact' to the internet ghouls by replacing a 'good' one with a 'bad' one? Maybe. Who knows, the thing might have taken a puke a 100 miles later. So I'll just fix it again, then move on and start thinking about all the other stuff that will eventually wear out. It still has the original brakes (they're at ~60%), original injectors/pump, turbo, water pump, etc....pretty much original everything. Knock on wood.
    • swathdiver
      6 Speed vs 8 Speed

      By swathdiver · Posted

      At peak temperature.  They get to cool down and warm up more, especially those with the external cooler.  I have three GMT900s and one of them has over 225K on its original transmission.  Fluid gets changed about every 36K miles, all of it.     It's not the bean counters, it was the government.  They had to meet CAFE standards and other government requirements.   To get around that, we tune them and modify them to our liking.
    • GMCustomerService
      Will not stay in Reverse

      By GMCustomerService · Posted

      Our customers' safety isn't something we take lightly. To ensure you get the proper assistance for your truck's repairs, please fill out the form at https://s.chevy.com/support-request with all pertinent details including your username.
    • GMCustomerService
      2026 Z71 Forward and Rear Park Assist help

      By GMCustomerService · Posted

      We appreciate you sharing your experience with your truck. To ensure we get you the proper assistance, please fill out the form at https://s.chevy.com/support-request with all pertinent details including your username.
    • newdude
      Radio Update

      By newdude · Posted

      PCM?  These don't have a "PCM".  Powertrain Control Module.  They have an ECM (Engine Control Module) and TCM (Transmission Control Module).   Do you mean update the radio?     You can check what version you have in the settings page.  Should be Y181 but there might be a newer build they can update it to.  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...