302/5.0 stock....runs normal weather the o2 is plugged in or not...can't figure it out...and there's a ticking that sounds like its comin from the oil pan area?????? Bout to do body work n other stuff soon so please help don't wanna waste time nor money

 

what year and what o2 sensor btw does the tick change when theres an increase in rpm or when its warm

 

Its a 90' and th sensor in front of where the cat used to be...and I think the tick gets faster with the rpms

 

The O2 should always be plugged in, but if it seems to make no difference then you likely have other problems, pull the codes to see what the computer has to say.

 

i fabbed up an exhaust when i first got my truck (10 years, 2 exhausts ago) i didnt put an 02 in because it was late when i finished, i drank a buncha bud lights, and i didnt feel like removin the y-pipe AGAIN to weld in a bung. well, that equated to drivin 2-3 years without an o2 sensor at all. i think (im not a ford efi guru) that the computer registers that the o2 is not there and runs based on information it stores in order to run well under a failed condition (i.e. a faulty o2, or no o2). well, i fabbed up another exhaust once my truck became "historic", re-installed a new o2 sensor, and i dont think i could see a lick of difference. i have '89 f250 with long tubes (y'd into a bullet muffler), open element filter, timing advanced, and some other nonsense probably not pertinent to the discussion. . . .

i say all this with hopes that the info i give is meaningful. but its sometimes tough to determine problems on these things. the 302 is such a ludicrous prospect in a 3/4 ton truck that somethin could be wrong, causing a "low-er power condition", and i would pass it off for normal.

 

correct me if im wrong, but if my theory is correct and the computer runs the motor on its previous input data (when it cant register a reading from somethin like the o2), then the fact that his truck runs well with it (the o2) unplugged would indicate more that the rest of his sensors/efi is working properly and thats why it runs good. . . my point being that if everything else is functioning properly and sending proper signals to the computer, then an unplugged o2 wouldjnt be the "end of the world" for his lil 5.0 because it would run off data tables that it has aquired with all the functioning equipment.

ive learned that its amazing how these motors will continue to run (in stock trim) despite virtual failure of almost everything that sends signals to the brain. yea, it might run like *****, but i cant tell ya how many times i made it out of a trail with an obvious sensor problem. and for the most part, ive always had more problem than 1 because for 1/2-5/8 of the trucks life it basically didnt matter if it ran or not, and i basically tolerated ill-running conditions on the premise that it "just didnt matter"

 

I wouldn't leave the O2 sensor unplugged just for peace of mind. My 302 has ticked since the day I got it and I've never been able to figure it out...Installed headers and full exhaust. No leaks at all. Drives me nuts.

 

tickin bein an exhaust leak? sounds like your egr is leakin. tear the wave off so you can gain access to the egr @ the intake manifold. be careful tho, the last time i took the bolts outta the upper intake manifiold it tsunami'd me off the truck and up my driveway. was bad.

 

You definitely should keep it. Without it the computer will run in open loop mode. While it may run ok, it won't be nearly as effecient with out it.

 

Yeah that's right, the EFI computer is programmed to account for sensor degradation and even failure in which case it uses the base or open loop tables to provide "safe" fuel and spark for a stock motor. But safe isn't the same as best, and while a motor will often run smoothly in open loop it certainly won't get the best gas milage and engine wear will increase with the extra fuel washing more oil then usuall from the cylinder walls.

All sensors are important to correct engine operation but the O2 sensor is the only feedback the computer has on how well it is doing at providing the correct A/F mixture, so you really do want it to be in the exhaust and working... particularly if you have or plan on modifying the motor. Even the SD system can adjust to modifications to increase airflow through the motor, it won't do it as well as the MAF system but using feedback from the O2 it will modify the closed loop tables to add more fuel which will make more power.

 

Eh I'm not gonna have time to take the upper intake off for a while. If I remove the valve and slide a spacer in to block it off between it and the upper intake will that stop the leaking or will air still be pumped into the tube under the upper intake?

 

it will be pumped out into the engine compartment, but blockiin off the egr at the front of the intake will prevent you from the possibility of suckin fresh air causin high idle whenever the egr opens. which, if you have a leak down there, will inevitabley happen. just a matter of time.

 

Very well said. It's there for a reason.

 

Sorry for the , but since we're on the subject of O2 sensors, I thought it would be a good place to ask. is there any real advantage to getting the 95.00 Beck/Arnley Oxygen Sensor vs the 45.00 Bosch? I mean can the computer tell the difference?

 

Yes there is an exhaust leak but I don't think that's what's makin it tick..sounds like its comin from around or above tue oil pan it get faster with the rpms..what's an "egr"???... and there is oil in the intake..just a little I'm thinkin bad rings the engine is just worn out...if I don't figure it out soon I'm gonna buy another vehicle....should I buy a new o2?..there not cheap so is there a way to test it..I'm sure it will run better wity a new one...if I remover it from the pipe cwn I tell its condition just by lookin at it??? Thanx again guys I really appreciate ur help...and do you need an egr valve with and after market exhaust..the pipe that ran to the exhaust rite after the cat is broken off