vristang

BINGO

Hydrocarbons foul up O2 sensors.

Some folks say to clean then with a torch, but too much heat can damage them too.

By soaking them in hydrocarbon rich liquid, you ensured they won't work properly.

You need to replace the O2's before investing any time and money in further diagnosis.

Let us know how things progress...
jason

ridemx129

ok i will replace them

otherwise what could it be?

mattdel

https://mustangforums.com/m_2355308/...tm.htm#2355308

WhiteFoxGT

I've replaced that sensor as well to no avail. Does anybody know why my car would run as rich as it does. I mean I havent changed much on this motor...stock injectors, TB, MAF, upper/lower intake and even a stock FPR. Do you think my computer swap could have made the difference? It seems like when I put in the A9L it made it rich as hell, maybe I should try my C3W....will that work with a T5 trans?

AdderMk2

you dont even know if your car truely does run rich. have you stuck a wideband O2 in your exhaust??? I can tell you that My car will make your eyes water as well... and you can stare at my wideband when it says im idling at 15.3:1

vristang

Even the mods here dish out incomplete info...

"The ECA reads the varying sensor resistance and determines the engine operating temperature, using this information to optimize the air/fuel mixture and ignition timing."
The computer doesn't read the resistance, it only sees a variation from the 5v reference being supplied to the ECT.

Also,
It is much better to check an ECT ina way that allows you to check the actual temperature of the water/coolant with a reliable thermostat.
Just checking with the sensor still in the heater tube is nearly useless. You have to know what the temperature truely is.




Have you pulled your diagnostic codes?
There is a link in my sig if you don't have a scanner.

If the computer change wasn't done correctly, then a problem could arise. Ford enjoyed changing the pin locations nearly every year.
Also, a wiring/ground problem could have started with the swap.

Another common problem is the ground wire for the O2's.
This wire seems to be forgotten when installing a new motor. Typically the ground is not properly mounted to the firewall, or corrosion has degraded the quality of the ground.
It is worth checking if the codes don't provide any meaningful info.

Not sure if it helps, but that is about all I can think of right now.
good luck
jason

Boss_Hotrod

What do you plugs look like? I put cooler plugs in an 8n that was running rich and it doesnt do it anymore.

ridemx129

ok guys i figured it out and after i did it i felt like an idiot

it was my spark plugs, every single one of them were fouled, i also replaced to cap and rotor and now it works!