Proactive or reactive - waste of money?

[scapino]

Hi All,
I've got a 2005 Ford Exp Sport Trac XLT 4x4 (build date of Jan 2005) with 130k miles.

No real problems over the years, worst was front bearing hubs failed @ 100k - oh and the rear calipers locked up around 65k; also the heater blower motor began squealing at about 100k.

So my Q is this - the exhaust has been "smelly" lately. She's not throwing any codes, but considering the age / mileage I thought I should do some proactive repairs. I'm considering replacing the EGR Valve, DPFE sensor, PCV, and O2 sensors (if I can find the O2's that is). Is this a waste of money to change them proactively? I'd be doing the work myself, so the parts (with shipping) total under $200usd.

Just wondering what other (pros) think about changing these proactively? I'm planning to keep her for another 75k miles - they are gonna need replacement in the near future anyway right??

 

[MidnightRebel07]

What exactly does the exhaust smell like? If eggs or anything close to that then it's the cats going bad. It is always a good thing to be proactive with maintenance on these items listed above.

I replaced my cats and y-pipe with Random Technologies stainless steel pre cat delete y-pipe and single stainless steel high flow cat that also increases the exhaust size to 2.5" from the stock 2.25". I bought these from Todd Z from Zabteck.com for less then the cost of oem parts.

 

[scapino]

Thanks for the heads up on Zabteck.com - thus far mine just smells like it's running rich, no rotten eggs smell. That is why I was thinking EGR and/or O2 sensors. One (or more) probably nearing it's end of life...

 

[MidnightRebel07]

You can clean the O2 sensors by using compressed air and a clean cloth rag "NO SOLVENTS or CLEANERS" you'll kill the sensors.

 

[Kiliona]

If you're not mechanically inclined or don't have a scan tool those things may be good to just replace, but if you have a scan tool and can datastream, check the o2's dpfe and egr before you replace them.

If I were you I'd do the pcv, fuel filter, plugs, wires, air filter, and all your fluids (diff gear oil, tranny fluid, coolant, and of course oil) if you're looking for preventative maintanence. If you're looking to cure the exhaust smell check for exhaust leaks (oxygen can leak into your exhaust fooling your o2 sensors into thinking it's running lean, so they dump in too much fuel and it runs rich), things leaking on the exhaust, valve covers for seepage, do the pcv, make sure your egr isn't leaking (pull it off and blow into it) and when it's off make sure it isn't stuck open, etc etc

Also just a thought, most places will do a 100 point inspection for you for cheap to free.

 

[scapino]

Well, I do consider myself to be mechanically inclined. I plan to replace the water pump (and fan clutch) this weekend to chase down a squeaky bearing - already replaced the Alternator, tension arm, & idler which cured up about 75% of the squeak. And as long as I'm that deep into it I'm gonna do the thermostat & housing before they blow a leak.

I did the plugs & wires about 50k miles ago; tranny & fuel filter about 20k miles ago with the front hubs. And of course the air filter when I had to change the blower assembly last month.

I have noticed some sort of leak near a couple of hoses connected to the throttle body (directly above the thermostat housing on left side of throttle body) - not sure if it's a loose hose or what. If I'm gonna pull off the EGR to check for being stuck I might as well change it at that point ($60 bucks at RockAuto). But the O2's are more problematic. First, not sure I can locate them all? Second, once I find them how easy (or difficult) is it to remove them? A coworker suggested that I'm going to need a torch to get them out - is this true?

 

[Galactica]

Never seen that. Ever O2 sensor I've ever replaced has unbolted with no issues. But I live in Oregon, where rust is not an issue. Not sure where you hail from.

 

[MidnightRebel07]

You don't need a torch. They sell a O2 sensor socket to remove them but I use a regular open end wrench. Make sure to unplug the wires from the pigtails on them so you don't twist the wires and screw them up. To remove them I run the truck until it's warmed up then let the pipes cool down alittle before removing sensors. This will heat up the threads in the bungs to allow the sensors to unscrew easier.

 

[Kiliona]

Well, I do consider myself to be mechanically inclined. I plan to replace the water pump (and fan clutch) this weekend to chase down a squeaky bearing - already replaced the Alternator, tension arm, & idler which cured up about 75% of the squeak. And as long as I'm that deep into it I'm gonna do the thermostat & housing before they blow a leak.

I did the plugs & wires about 50k miles ago; tranny & fuel filter about 20k miles ago with the front hubs. And of course the air filter when I had to change the blower assembly last month.

I have noticed some sort of leak near a couple of hoses connected to the throttle body (directly above the thermostat housing on left side of throttle body) - not sure if it's a loose hose or what. If I'm gonna pull off the EGR to check for being stuck I might as well change it at that point ($60 bucks at RockAuto). But the O2's are more problematic. First, not sure I can locate them all? Second, once I find them how easy (or difficult) is it to remove them? A coworker suggested that I'm going to need a torch to get them out - is this true?

Soak them in penetrating oil, then just pull em off with an open end wrench or even a crescent wrench. Unless of course they look rusty, if that's the case don't risk stripping it, get an o2 sensor socket that's 6 point (not 12) and use that. The socket is basically a normal deep-well socket with a hole cut in the side so you don't smash the wires.

Midnightrebel has it right, unplug them first to avoid twisting the wires.

Also if you ARE mechanically inclined, and that includes obdII inclined, grab a scan tool and watch the cross counts on all your o2 sensors. I believe a good sensor has crosscounts of 5-8 a second? but look it up to be sure. anything 3 or under they need replaced. (this is assuming your engines running good, if you're running rich or lean your O2's may not have any crosscounts and still run fine). Make sure the vehicles in closed loop when you do this, and to make sure it's running well make sure you're long term fuel trim is at a decent level +-4% or so? if it's +20 percent or something you're running way lean and have another problem.

In case I'm speaking a foreign language let me explain, your computer watches your o2's to fine tune fuel trim, so you're car should run very close to stoich (perfect air/fuel mixture) while in closed loop (o2's heated up enough to provide input to pcm). the o2's send out a signal thats something like 100-900mV's. 100 being rich 900 being lean 475 or so being stoich. (I may be backwards on rich/lean, it's been a long day). The o2's should read either barely above or barely below stoich, when they cross the point of stoichiometry it's 1 crosscount (going from rich to lean or lean to rich) so the more times they do this a second the more accurate and the better they provide input to the computer. Using a scan tool you can see how many crosscounts a second the o2's are giving you. You can see if the o2's getting lazy and needs replaced.

Anyways point being, if you understand obdII protocol it's a very simple thing to see if you're o2's are working like new or needing replaced. I only suggest this because to me those sensors are a little spendy to replace "just in case" but the other things you're doing/have done (egr, fuel/air filter, plugs wires fluids) are all very good preventative maintenance items.