02 sensor location on 4.0

[94Splash4x4SC]

does anyone know how to get to the o2 sensor plugs from what i've seen they're ontop of the bellhousing. the only thing i could think of to get to them was drop the rear tranny mount but i really don't want to go thru with that.

 

[FMNavajo]

94Splash
I have a 92' Navajo and when I replaced mine it wasn't that bad. The sensor is located just in front of the Catalytic converter, screwed into the pipe and the connector is about 12" above that. I did the plugging and unplugging from the passenger wheel opening. You can also reach it by reaching over the upper intake manifold if you climb up in your engine, (not the easy way). The other way is to reach it from underneath just, MAKE SURE THE ENGINE's COOL!.

Good Luck,
FM

 

[Gofast]

O2 sensor location on a 94, It's baaaaaaaddd

I wish you the greatest of luck. I swapped both of mine out before MOAB. My secret..... Well after several attempts I took it to Ford. $72 later mine were installed.
I could only get my finger tips on one of the plug ins. I though about making a jumper to extend the plug-in to where I could actually reach it for future replacements.

Good Luck and pass on any tips you may discover on this one.

 

[flyguy]

Ouch. I have a 94 and was wondering when those things should be replaced? How can I tell when my o2 sensor is in need of replacement?

nick

 

[FMNavajo]

flyguy,
I replaced mine when I had the check engine light come on and after checking the codes I found that between the fuel pressure regulator and o2 sensor it was reading the wrong fuel to air mixture. I also cleaned the MAF at the same time and the problems went away. (sorry I forgot the codes and I don't have my book here to check.

FM

 

[flyguy]

My problem is that Im getting terrible gas milage. I was told those two are the first things to check, however Im not getting a check engine light and the smell that people describe that goes with a bad fuel pressure reg is not there. Any other ideas?

Nick

 

[Gofast]

O2 sensor life?

flyguy, I've asked this question on 2 different sites now. I got a very detailed answer from the Firebird club, but can't find the post. Basically, The highest estimated life I found was around 60K miles. I would only throw a check engine light when pulling a trailer or going 75 + on the turnpike. My gas milage took a nose dive. That's when I finally started tracking down the cause. I replaced both fuel pressure regulator & the O2's at the same time.

I have no more pinging, no check engine light, and an improvement in gas milage. My gas milage did not make a huge improvement since I also lifted the truck, put 33's on it and a confer rack that acts like a parachute.

Good luck finding the plug in for the O2's.

 

[flyguy]

Haha... yeah my milage sucks. But I have also been considering another possibility... That I drive like an idiot. Ill hit 80Mph redlining to go across the street. Heh. Im usually not that bad but you never know with me. Well.. if you say its 60K miles I should just go ahead and replace them. Where do i pick up 02 sensors? Does quality matter or is that something I can pick up at any auto shop? Know how much they run and how many I need? Also, were you getting the funny exaust smell everyone talks about? I took a big whiff (and passed out ) and didnt smell anything...

Nick

 

[Gofast]

O2 price

They were not cheap. I got the Bosche (sp?) O2's from autozone for $40 a piece ( I think ) you need 2 for a 94. I paid Ford $72 to install them. The real trick was getting a dealership to install non-Ford parts. It was not a cheap deal, but it really helped the way it ran. It seems that the computers affect so much now, a bad sensor or plug and your truck will run like crap since it's trying to compensate.

Good luck with the install.

 

[flyguy]

Hmmm... I have a crappy mecanic who will do it cheaper probably... hes an idiot though. I think you need to drop the E for the right spelling.. I think. oh well. I guess I can buy them and "try" and do it myself. And then when I cant Ill take it in.

Nick

 

[flyguy]

Okay... one of th o2s is by the cat right? Where is the other one at? Also, about ford not installing non ford parts.. guess who makes the 02s for ford? Bosch. Just thought that was intresting.

Nick

 

[niceguy]

O2 location

Hi Nick - On your '94, you'll have two O2 sensors - one on each downpipe that comes from each exhaust manifold. Crawl under the truck (on ramps is much easier) until your head is under the transmission tailhousing. Just follow the exhaust pipes back up towards the engine and you can't miss 'em. The driver's side is easy to get to; the passenger side is a pain. But getting to the sensors is the easy part. Getting to the wire connectors is the real problem.

If you're still planning your head swap, then that would be the ideal time to do it. If you do it at some other time, then make sure you get the truck up on ramps, then open the hood and let it sit for a few hours to cool. The exhaust pipes are HOT and take awhile to cool down. Even running the engine for 5 minutes to move it and get it up on the ramps warmed mine up a bit (after I had my wife not drive it all afternoon so it could cool down - duh!).

Have fun ;-) - that $72 dollars sounds like a bargain to me...

 

[flyguy]

AH!!! You guys are whiners!!! Those 02s took me a total of 5 min tops... and that only because I had no ramps and just slid under the car!!! Hehehe. They are all in and ready to sensor 02. Still, I wish my headers were in so i could do all this at once...

 

[niceguy]

OK, smarty pants...

Then do-tell: what was your secret? Did you do it with the intake and heads in, or out? If in, then how did you get to those %$^*&@ connectors in such quick order?

Michael

 

[flyguy]

Haha... the heads were still on, but I made my mom lay on the engine and grab em when I fished em up to her. hehe. Unscrewing the o2s were easy too.. a bit harder because I had to use an adapter to fit the 02 socket to 1/2 inch. but I really do recommend getting a family member or girlfriend and just laying them up on the engine for anything. They come in handy sometimes....

Nick

 

[Isles4evr]

LOL, very nice. I am going to replace my o2 sensor sometime this weekend I think... if I can fork over the money. I'll tell my girl friend to lay overtop the engine and hold the wires. Yeah right... it would be interesting to see though. I'll ask her tomoroow and see what she thinks about it .
Chris

 

[RonSC]

FLYGUY-

So PLEASE TELL! Did you notice any improvements in gas mileage after putting in the new O2 sensors?

I have done just about everything to my 91EB to try and improve gas mileage with no such luck. Im getting 200 to 210 miles on a full tank of gas with air condition off!

I have a drop in K&N filter with the punched hole bottom airbox, Bosch +4's, changed all my fluids and flushed out my transmisson and engine oil. Jet Thermostat. New fuel filter. Had my throttle body and fuel injectors cleaned from the dealer.

Only think i have noticed was improved performance. Still no improvement in gas mileage. Wondering if new O2 sensors will work before i spend more $$ on Superchip, Splitfire wires and Flowmaster muffler.

 

[F'in Bob]

Hey Flyguy, 98 TM heads?

Flyguy, what information can you pass on about the heads you have listed in your signature?

Bob

 

[flyguy]

Well... lets see... I get no milage at all. ya wanna know why?! Cuz a majority of my engine is sitting on the garage floor! Hehe. Im in the middle of a head swap still (those 98tm heads... acually.. i think they may be 99's but I think the 98 and 99 are the same) If you want to check out the thread Compression Ratio??? I have pictures and everything about my head swap so far. I just had to drive outta town yesterday to pick up rocker arm bolts... anyways... I dont know what my milage is yet.. but the O2s did look pretty beat... and ford that o2s are the main reason for my milage to be poor (next in line was the fuel pressure regualtor)... Ill post my new milage when I get my car running... of course I have alot of other mods going on at the same time.. so I dont know how that will effect it... OH! And the new heads. All they do is increase your compression ratio to 10:1 from 9:1... I should be able to get some more power from it.. plus I replaced my pushrods with lightwieght ones... yup yup. Its kinds fun...

nick

 

[flyguy]

Oh... by the way. If you have a 91.. im sure its long been time to replace the 02s. I think they should be done about 60,000 miles or whatever. I could be wrong though. from what i hear you should be getting around 17. Go here.. http://www.fordpartsnetwork.com and ask for torrie... they hook you up!

Nick