OK, I have a long story that goes with this, but I know a lot of you probably don't want to read it, so I'm going to front-load this with the fun part - identifying parts in an engine bay! I have a 2000 Ford Ranger V6 4.0 OHV and I'm thinking I have a problem with a vacuum leak. I took a cigar and I detached what I believe is a vacuum line (in blue):



When I did that, I saw smoke coming out of the thing it attaches to on one end, but I have no idea what that thing is, so I don't know if it's supposed to be vacuum tight, and I don't know how to fix it:



Here is a view of the thing from the other end. It's very close to the A/C compressor, but I don't think the two things are attached:



I also took a tube and put one end in my ear and the other end near the cap thing while the engine was running, I heard hissing, so I detached the TPS and sprayed it with WD-40 and heard a noticeable change in the idle speed, so I think that must be the problem.

That said, I also blew smoke into the other side of that vacuum line and found this bad boy in what I'm taking the intake hose:



Which I then repaired using hose repair tape (first layer) covered in chewing gum, then aluminum foil and then taped over using duct tape. I don't see any more leaks on that side of the hose, but the problem is that my truck still doesn't get much power at all. Maxes out at around 55 mph. When I got the codes pulled yesterday, they were:

P1121: Throttle position sensor inconsistent with MAF sensor
P0171: System too lean (Bank 1)
P0174: System too lean (Bank 2)
P0351: Ignition Coil A Primary/Secondary Circuit Malfunction
P0352: Ignition Coil B Primary/Secondary Circuit Malfunction
P0141: O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)

I don't have my OBD-II reader here (I moved to TX just about a month ago, and my wife is coming with all our stuff next week), so I don't know if any of those have changed since I repaired the intake hose. I don't think the O2 sensor problem would cause the power loss, at least not acutely, and I don't have any cylinders misfiring, so I'm guessing my main power problem is the vacuum leak. I'm really just trying to get this fixed well enough that I can drive to work like normal for about 1-2 weeks. After that, my wife will be here with my motorcycle and car, and I'll be able to actually take this (my only vehicle) to the shop without worrying about how to get to work.

So - does anyone know what that part is that is leaking or potentially have any advice about how to fix it?

http://easyautodiagnostics.com/ford_...gr_valve_2.php

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1997 4x4 Mazda B4000 SE, Ext.Cab

Actually, turns out it's a Canister Purge Valve Solenoid: http://www.autozone.com/autozone/par...779340_0_9091_

Hopefully it's not supposed to be vacuum leaking, otherwise I'm throwing a $70 part at this problem for nothing.

Well, I replaced the part and it no longer has a leak, I've tried spraying all the vacuum lines I know about with WD-40 and no change in the idle speed, but my truck still has terrible power! For whatever reason, patching a bit hole in the intake tube and a vacuum leak has left the performance of the truck unchanged! Does anyone have any ideas? I'm getting desperate here!

P1121: Throttle position sensor inconsistent with MAF sensor ....Test the TPS and clean the MAF,,,A bad TPS is going to screww with you!!!
In fact it's possible that's it's causing the "LEAN" codes....

P0141: O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)
Find and replace the Fuse for O2 heaters!!!!

P0351: Ignition Coil A Primary/Secondary Circuit Malfunction
P0352: Ignition Coil B Primary/Secondary Circuit Malfunction
Wouldn't hurt to do a resistance check on the pack with a meter if you have one with you or take them to autozone and have them tested, that said, I think that this might be "bogus" code that just popped up! That would be my last check to do...If you had bad coil packs I doubt the truck would start.

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2011 Ranger XLT 2x4,4.0 SOHC, 5 Speed Auto, 3.55 Rear. Oxford White.

Simplicity is the ultimate sophistication.

Torque it down till it breaks off, then back it off 1/4 turn.

Rangerman - Thanks for the info. I agree about the ignition packs being bogus. I haven't focused on that at all because I did a resistance check on the ignition coil pack some time ago and they were all the right value (14kish per pair).

I am going to check the TPS resistance tonight, but I've already cleaned both the MAF and TPS. My understanding is that that particular set of codes is very indicative of a vacuum leak, and I found the large leak in the intake tube and the smaller leak in the canister purge valve. I've since replaced the canister purge valve, but the power in the truck didn't return!

I went to autozone again to have the codes pulled (my wife has my OBD-II reader because I accidentally had it sent there!) and I'm now down to 4 codes: P1121, P0141, P0174 and P0351. So basically I'm no longer getting a lean code for Bank 1, and I'm no longer gettin the bad ignition circuit B.

My understanding is that the O2 sensor is likely to cause rough idle, but not low power. I'm wondering if I have another vacuum leak somewhere else, but I can't find a diagram of where in my truck all the vacuum lines are, or I would test them with the cigar trick and/or the WD-40 trick.

Make sure you don't have a vacuum leak around where the TPS and MAF mount too, This can have you chasing your tail looking for a leak down steam...

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2011 Ranger XLT 2x4,4.0 SOHC, 5 Speed Auto, 3.55 Rear. Oxford White.

Simplicity is the ultimate sophistication.

Torque it down till it breaks off, then back it off 1/4 turn.

Yes, I sprayed those areas with WD-40, no change in the idle speed. Also, since I found that hole in the intake tube by blowing smoke into that one vacuum line, I think I would see the smoke coming out of those mounts if there were a leak there.

OK, I tested all the vacuum lines I could find and no new leaks. WD-40 had no effect on any area I could find either.

When I checked the TPS voltage, it varied from 0.6 V (idle) to 0.5 V (wide open), and when I actually pulled it off, I tested the resistance as a function of throttle position and it varied from 3kOhms (closed throttle) to 0 Ohms (wide open). Is this normal?

The engine has to be warmed up for this test to be 100% effective, although the Throttle Position Sensor Test is done with the engine off. So if the engine is completely cold... start’er up and let’er run for about 20 minutes.

Select Volts DC mode on your Multimeter and with the engine off, probe the Gray with White Stripe wire (coming out of the Throttle Position Sensor’s connector) with the RED Multimeter lead, using an appropriate tool to pierce the wire.

Ground the BLACK Multimeter Test Lead on the Battery Negative Terminal and then turn the Key On but don’t start the engine.

The Multimeter’s initial Voltage (of .9 to 1 Volt DC) should increase smoothly as you open the Throttle Plate to its Wide Open Position. At Wide Open Throttle, the reading on your Multimeter should read about 4.5 to 4.9 Volts DC.

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2011 Ranger XLT 2x4,4.0 SOHC, 5 Speed Auto, 3.55 Rear. Oxford White.

Simplicity is the ultimate sophistication.

Torque it down till it breaks off, then back it off 1/4 turn.