extra oxygen sensor?

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ron17571
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extra oxygen sensor?

Post by ron17571 » Sat Jan 06, 2018 1:43 pm

I plan on doing a MAF conversion on my 92 f-250 with a 460 and an auto c-6. so far I have thought of using an f3zf -Ca.computer.A remanufactured Cardone unit for a cobra mustang.I hope this is set for #24 injectors. My question is about needing an extra oxygen sensor.I have read about needing it.I plan on using an overlay harness.I imagine this has the needed wire for hooking up an extra o2 sensor. My truck already has dual o2 sensors by the cat.convertors.I would hope they would still work with that different computer.I am funny in that I plan on keeping all my emissions equipment intact. ok, I am funny in many different ways! Any advice or info would be appreciated.

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skunk
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Re: extra oxygen sensor?

Post by skunk » Wed Jan 10, 2018 7:53 pm

Nothing funny about keeping your emissions equipment...good on you!

Sounds like you are not tuning but instead wanting to just run the stock Cobra ECU. You can do it but you have alot more research to do. Yes it runs MAF and 24# injectors and has provision for 2 o2 sensors (one for each bank). If you already have dual O2 sensors pre-cat one on each bank......you should be able to make it work. Your other concerns will be spark and fuel firing order and using the appropriate MAF. You really want to be able to dial it in properly .....you won't be able to without tuning in my opinion.

Good luck
John
1987 Turbocoupe.
A3M1/A9L, BE/EA, Tweecer RT.
306,Single Turbo, Ported E7's, Ported Stock Intake, 42lb Matched Green Tops, PMAS 3" Blow-Thru Protube (42# supercharger calibrated),T5z, 3.73 gears
..... Nothin Fancy.......Just something to keep me from the honey-do list.........

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cgrey8
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Re: extra oxygen sensor?

Post by cgrey8 » Thu Jan 11, 2018 8:34 am

Your motivation is right in wanting to run two banks instead of just one. However, getting things running right without a tune is difficult and may prove more difficult than you imagine. Add to that, the things that need changing are not difficult to do in a tune and once you make the investment to make the tuning changes necessary, you don't have to stop there. You have the freedom to do other common mods, even simple ones, for example:
  • Upgrade the MAF to a slot style (and do so for CHEAP). I upgraded away from my C&L for $25?
  • Upgrade the Throttle Body
  • No longer locked to old 24lb EV1 era injectors. You could use more modern injectors that atomize better and deliver fuel FAR more accurately than anything from the 80s and early 90s.
  • The typical and more costly, but bigger return mods (e.g. H/C/I/E)
As for maintaining emissions, unless you are in an area that requires them all OR you are just that civic minded that you feel the need or obligation to keep it all, there's only 1 emission device that actually has worth and it's often the first one that people ditch...the EGR. Smog pumps, canister purge systems, fuel tank pressure sensors, and secondary O2s (the ones after the CATs), and the CATs themselves are all there 100% for emissions purposes and offer no benefit to the running performance of the engine. The EGR is different. At cruising conditions, there are actually benefits to a small amount of EGR in that it allows you to run a slightly higher advance because the presence of EGR gas often has a dampening effect on detonation. It's minor, but there. At best, having retaining EGR will only increase MPGs by 1/2 a point. With a 460, I doubt you would ever notice it. It'd be akin to removing the mechanical fan and replacing it with electric fans.

I maintained the EGR on my engine when I did the swap from a 2.9L V6 to a 302 back in 2005 because I thought I'd need it to pass Georgia emissions. What I didn't realize is the "inspection" here is a joke. They turned a blind eye to the fact that there was a V8 where the VIN said there should be a V6. As long as the sniffer test passed and the gas cap was good, they couldn't have cared what was under the hood. They didn't even look to see if I had CATS or something that looked like CATS in the exhaust. Ironically, the 1989 2.9L had a factory EGR delete plate. Only the California-sold Rangers got the EGR and smog pump. All others got that plate and a block-off bolt in the exhaust manifold. The catch with pre-OBD-II cars is you actually have to pass the sniffer test. The good news is if the vehicle is having trouble or you suspect it's on the verge, just retard the timing WAY back and it'll pass. Some have even reported they can pass CATS! When I got my high compression 331 completed, I had to get it tested and I honestly didn't know if it'd pass or not given it was high compression. So I retarded timing back to 18 across the board, where it would've been in the 30s for the RPM/Loads it was tested at. It performed way better than the 302 did a year before. The 302 was flirting with the NOx limit.

Now that most cars are OBD-II, it's even easier to get a vehicle to pass here in Georgia since the state computer trusts the on board computer not to lie. Well when you are in control of the onboard computer, you simply tune it to report that all checks are active and PASS, then the state computer's happy and you get your tag for another year. So you no longer have to go in there with an "emissions" tune. Every now and then, they'll still do cursory idle-sniff tests. And from what I understand, they are only ever done on vehicles that are commonly modified. My 97 Ranger has never been flagged for one, but a guy that works here has his 2003 Cobra (which is bone-stock) flagged quite frequently.

The 89 hasn't had to pass tests for quite some time now. Once vehicles are over 25 years, they aren't required to take the test any more here in Ga. Despite not needing to pass, I still keep the EGR working, the canister purge box where it's always been (and plumbed in). And I assume the CATs are still good. I don't know why they wouldn't be. But if any one of them gave me trouble, I wouldn't bat an eye at ditching them if that was easier.
...Always Somethin'

89 Ranger Supercab, 331 w/GT40p heads, ported Explorer lower, Crane Powermax 2020 cam, 1.6RRs, FMS Explorer (GT40p) headers, Slot Style MAF, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, Innovate LC-1, GUFB, Moates QuarterHorse tuned using BE&EA

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scopx
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Re: extra oxygen sensor?

Post by scopx » Tue Jan 16, 2018 5:25 pm

This is my first post.
I joined as a EEC-IV truck bought for an immediate towing requirement, has way too little power for what it should have. The towing issue resolved, now have an opportunity, and the time to see what is going on.
It is a 94 F350 Dually, 460 4:10s.
In driving, is would suggest that there is a restriction in the exhaust system as the higher the RPM, higher coolant temps go. (in addition to the "No beans" condition.) I do not know if headers were standard or not, but this has chrome headers, into 3" header pipes, then into a "single" muffler system of about 2 3/4" size! Thinking the cat was blocked, cut it off to find it was a straight through design muffler. No restriction there. So now have removed the muffler and tailpipe and system is 3" all the way.
Only "flags" in running faults, were the exhaust thermofactor(?) pump (which in reading, supposedly not affect performance as all passive,) and a transmission (fault 131?). However, trans has been altered (apparently) as will chirp tires empty (with 215's) if you are in a hurry. And yes, it will cause drinks to slop out of the cup.
So, all of that was leading up to- I find only an upstream 4 wire O2 sensor on this vehicle, no downstream. I have yet to drive (had snowstorm yesterday)to determine if the muffler was culprit, or problem lies in engine management.

Do have another area of suspicion, which is poor vacuum, which could be throwing the system into a (open or closed?) loop. Do not know enough to correctly address the terms. That's why "I here folks" -to learn. So be patient and not take the "whupping stick" to me yet. I learn slow, but do learn.

scopx
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Joined: Tue Jan 16, 2018 3:06 pm

Re: extra oxygen sensor?

Post by scopx » Tue Jan 16, 2018 5:35 pm

Adding to my first as "mufflers" may little confusing here. The factory type muffler was the one left off and the straight through type reinstalled, with 3" dump.

motorhead1991
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Re: extra oxygen sensor?

Post by motorhead1991 » Tue Jan 16, 2018 6:33 pm

scopx wrote:
Tue Jan 16, 2018 5:25 pm
This is my first post.
I joined as a EEC-IV truck bought for an immediate towing requirement, has way too little power for what it should have. The towing issue resolved, now have an opportunity, and the time to see what is going on.
It is a 94 F350 Dually, 460 4:10s.
In driving, is would suggest that there is a restriction in the exhaust system as the higher the RPM, higher coolant temps go. (in addition to the "No beans" condition.) I do not know if headers were standard or not, but this has chrome headers, into 3" header pipes, then into a "single" muffler system of about 2 3/4" size! Thinking the cat was blocked, cut it off to find it was a straight through design muffler. No restriction there. So now have removed the muffler and tailpipe and system is 3" all the way.
Only "flags" in running faults, were the exhaust thermofactor(?) pump (which in reading, supposedly not affect performance as all passive,) and a transmission (fault 131?). However, trans has been altered (apparently) as will chirp tires empty (with 215's) if you are in a hurry. And yes, it will cause drinks to slop out of the cup.
So, all of that was leading up to- I find only an upstream 4 wire O2 sensor on this vehicle, no downstream. I have yet to drive (had snowstorm yesterday)to determine if the muffler was culprit, or problem lies in engine management.

Do have another area of suspicion, which is poor vacuum, which could be throwing the system into a (open or closed?) loop. Do not know enough to correctly address the terms. That's why "I here folks" -to learn. So be patient and not take the "whupping stick" to me yet. I learn slow, but do learn.
It took me a while to remember which term was which, even after learning about their operation in high school (a really good "auto shop" course).

Closed loop uses the sensor (think "closed off" at stoic)

Open loop let's the computer loose and commands what it thinks it needs based on MAF/VAM/MAP and a few other inputs.
1990 Ford Ranger FLH2 conversion. Ford forged/dished pistons, Total Seal file-fit rings, Clevite rod and main bearings, Clevite cam bearings, IHI turbo, Siemens Deka 60lb/hr injectors, Ford slot MAF in custom 3" housing. Moates Quarterhorse with Binary Editor, using the PAAD6 database.

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