Hi all.

I recently picked up a 2001 Montero Limited for a very good price. The owner kept it pristine and has only 115K. The car did have the Service Engine Soon warning and they had it fixed the first 4 times for different things. They also did all the brakes, tires, timing belt and new seals for any leaks done. Now it came up with another code for fuel injectors and according to Midas and they need to change all of it. That seems odd that all need to be changed but I'm not sure since I'm not familiar with the vehicle/motor. Anyway, I'm taking it to my mechanic tomorrow to hopefully solve it but I was also noticing the RPM going to 500 RPM at idle so I may have an IAC issue too. It runs like a champ other than those. That's enough.

I'll be reading up a lot of the info on the forum and hopefully learn more including the butterfly issues. Yikes! I'm also a member of other forums so hopefully I can pick stuff up quickly. If you have any advice please post it up. I'll gladly accept it.

 

What is the exact "fuel injector code" that is set? Also post Frieze Frame data for the code if you have it - it will help. I seriously doubt that you have to replace ALL injectors. Don't hurry up with it just yet

 

I'll try to get it when my reader comes tomorrow if I can. I also took it to my mechanic and he said lean bank one and suspects it's the Air Mass Sensor similar to another Montero he just worked on. I went ahead and ordered an Autozone Duralast brand over an eBay type for this one and put it in tomorrow. Unfortunately, I couldn't find a boot to go with it so I'll check eBay for that.

 

On Monteros both engine banks get air supply from one intake and one Air Mass Flow Sensor. If your issue was related to MAF, you'd have the lean code on both banks. Since it is only on bank 1 - something else is causing this issue.

 

Well, we tried to get the bolts off the MAF and it won't budge and actually cracked the plastic tabs before I read your response. Now I need an intake box cover as well. 😂

So P0170 & P0125 & P0125 P. First time I used a reader. Should I go into it further? I'll check again tomorrow.

 

P0170 means the system is running too lean and outside of allowable fuel trim compensation values. Are you able to pull Freeze Frame data from these codes? It is possible that both of these codes are related. If it was up to me, I'd tackle the P0170 first.
Possible causes - vacuum leak in the intake manifold (could be as insignificant as a cracked or disconnected vacuum hose), bad MAF sensor (this would not be my first suspect), bad fuel pump (low fuel pressure), or clogged up fuel injector(s). I would start by checking for a vacuum leak first. Check all vacuum hoses, check for cracks in the air supply hose or any loose hose clamps. If you've cracked the air filter housing - you can slap some duct tape on the crack to seal it until you get replacement. Another useful trick to detect vacuum leaks is to get a can of starter fluid, run engine at idle and squirt small amounts of the starter fluid around all the hoses, air supply hose, around EGR valve and at various areas of the manifold connection to the block/heads. Use a little straw to get the starter fluid right up to the specific components. If at any time engine speed changes from idle and RPMs increase when you spray fluid in a specific spot - you found where the extra air is getting into the system. That air is not measured by the MAF and that is "confuses" the PCM causing the error code you are seeing on the scanner.

 

Great information! Thanks and I will try to getthe code details. I'll also check on the leaks but so far the hoses look fine. I will check the boot on the intake. It does look ond but seem ok when I checked it but I'll do a double.

 

Looks like my new scanner doesn't have freeze frames. I'll try Autozone and possibly order a newer version. I also found a new air inlet so I'll be ordering that too while I check for leaks. I didn't see any visual evidence of it but I'll try to use my carb cleaner to see.

 

Carb cleaner might work too. You'd be surprised how small of a leak you need to throw things out of whack for the computer. The reason you want to see the Freeze Frame (FF) data is to see if only one bank of the engine is affected by the lean condition or both. That helps in further diagnostics.

 

We did the carb cleaner check and negative results. No leak. I'll clean the IAC and see if that helps the idle. I have a new one coming in in a couple of days.