Here's a slide show I pulled together this morning after I removed the ECU from my 99 Maxima. I read some ECU removal instructions and was able to remove the ECU in about 20 minutes or less.

While I purchased a new Offset Ratchet Screwdriver Tool with a #2 Phillips, once I started the job, I quickly realized my existing 8mm Swivel Head Gear Wrench would stay mounted on the ECU bracket bolts and make removal go faster.

Here's a link to a PhotoBucket Slide Show that shows covers the steps I followed during removal.

Set your viewing speed in the lower right hand corner of the slide show screen.

http://s286.photobucket.com/user/Rid...99/ECU_Removal

If the slide show doesn't work out for some users, I posted the slide show IMG images in this message.

Individual Slide Images Below

Tools



Step 1 - Disconnect Battery



Step 2 - Remove ECU Covers



Step 3 - Remove ECU Wiring Harness



Step 4 - Remove Left Side ECU Mounting Bracket Bolts



Step 5 - Remove Right Side ECU Mounting Bracket Bolts



Step 6 - Lower ECU Away From Mounting Bracket



Step 7 - Remove ECU

 

I can't get a damn 8mm on those screws. How did you!?

 

Hey Chris - It looks like the earlier models used #2 Phillips head screws. I had initially purchased a Offset Ratchet Screwdriver Tool with a #2 Phillips, thinking it would work.

On the 99 model. I was surprised/shocked to find 8mm heads. Over the past year, I've seen it both ways.

 

Those damn screws on the passenger side are impossible to get to.

I have a offset ratchet screwdriver and still can't get to them. Driver side was a pain but they're off.

 

I read where somebody took some small pliers or needle nose vice groups and grabbed the screw by the head to start it turning.

You're not kidding it is PITA to remove the passenger side.

 

**** it, I might try that. Or just leave the Nistune ECU off to the side and call it a day.

I'm just not sure if I can let the ECU bounce around like that. No one sits on the passenger side but roads aren't perfect on my daily commute.

 

Here's an old thread on ECU removal.

https://maxima.org/forums/4th-genera...u-removal.html

I pulled a 96 ECU from a salvage yard car that had screws in it like the one in the picture below. Over the past three years, I've pulled/swapped three 99 model ECUs. Somewhere during the 4th gen run, the screws changed from round head to 8mm.

 

It's funny. I have that exact Neiko tool which worked on the driver side.

I'll attempt the passenger side again tomorrow.. maybe..

 

I removed the ECU successfully today. For the front passenger side screw, I was able to use a needle nose which loosened it easily.

The rear took me a while. I couldn't get the needle nose on it but was able to trim down the Philips attachment for the Neiko tool to really shorten it up. Here you can see how much shorter it became compared to the offset screwdriver. Made the job a lot easier.



When I put in the Nistune ECU, I only installed the front driver side screw. Don't got time to mess with all four of them bishes again lol

 

Chris - Good to hear you made it. I wouldn't worry about it. I think there are many ECU's that have been mounted without the one of the passenger side screws.

 

I've got no passenger side and only the front driver side screw in place. It'll be fine. The tight ECU connector/wiring should hold it snugly in place along with that one screw.

Maybe I'll get some bolts that I can use a swivel head gear wrench on

 

The tool on the left is the only way I could get the job done years ago. I remember cussing up a storm trying to remove those little ****ers too.

Like you, I only have one screw securing it in place. With the EU tied to it on the opposite side, it's not going anywhere.