using wideband and disconnecting stock 02's

[Overboosted]

I have just done alot of reading about guys who have disconnected the stock o2's and just tuned with a wideband and I think this is something I would like to try.

The only issue I have read is that the ecu will throw a cel and go into limp mode (although it doesent seem to effect performance). Instead of this I am wondering if it would be possible to just keep the ecu in open loop mode via thermostat temp sensor?

If I got myself an aftermarket water temp gauge so I can still keep track on the temp accuatly is there anyway I could put some sort of resistor or something in the wire running from the temp sensor to the ecu and fool the ecu into thinking its always too cold to run closed loop?

What do you guys think?

[Monster Stealth]

Some widebands have a 0-1v narowband output that you could splice into the factory wiring if needed. That would be an ideal option imo

[Overboosted]

Originally Posted by Monster Stealth

Some widebands have a 0-1v narowband output that you could splice into the factory wiring if needed. That would be an ideal option imo

Does aem 6 in 1 have this feature? I guess I could then unplug my stock o2's. Would this 0-1 v feature just fool the ecu into thinking it's getting a reading and freeze the trims or would it deliver a proper reading and the ecu could adjust the trims properly according to the wideband reading?

[Monster Stealth]

It would work just like your stock narrowband unit. The downside to this is that if you mount the wideband in the stock location. You will be getting a AFR on only one bank and not the combined AFR. IMO the rear precat would be the best just because the rear bank tends to run a little leaner.

[Overboosted]

Originally Posted by Monster Stealth

It would work just like your stock narrowband unit. The downside to this is that if you mount the wideband in the stock location. You will be getting a AFR on only one bank and not the combined AFR. IMO the rear precat would be the best just because the rear bank tends to run a little leaner.

I'm not installing the wideband in the stock o2 location, I am installing it in the downpipe so it gets a reading for the whole engine. I am just wondering how the wideband would work for trims. Well this seems like a great option.

I guess I would need to split the wideband 0-1v output to feed both stock o2 feeds and then I can unplug the stock o2's and the trims would be more accurate than stock.

I am sure there are threads about wiring in the widband to the ecu's o2 feed, I will search for those.

Thanks

[Gray Haze]

Just live with the CEL. Its worth it.

[Overboosted]

Originally Posted by Gray Haze

Just live with the CEL. Its worth it.

Why when I can input the wideband to the stock o2 feed and have the ecu correct my trims with the wideband? For the small amount of wiring I would need to do extra it seems worth it to have a reliable cruising tune doesent it?

I also find tuning easier using the trims to compensat for my 720's and ford MAS. As my load increases my trim o2 shows richer conditions that leans out again if I decrease the load no matter what rpm I'm at. Even if I play around with the low and mid load setting on my arc it doesent really change.

My current tune has the low trim at like 130% and my mid at like 85%, this keeps my o2 trim close to 100% at all cruising loads at all rpm's. Which is a good tune for a narrowband tune atleast.

I can only imagine it would be the same conditions using the wideband so if I could keep my trims working, bonus.

I want to eliminate the stock o2 sensors since they seem to be on there way out (they no longer cycle at idle) and then I wont need to replace them.

[keithmac]

Most people pull the narrowbands to stop the ECU trimming at all (all trims stay at 100%) and wrecking/ fighting the tune.

Running simulated narrowband into the Mitsu ECU will be no better/ more accurate than GOOD stock narrowband sensors, the ECU is still just looking for the 0.5V crossover point.

I pulled the stock o2 and it allows me to run much leaner at some points in the map than stoich, benifitting fuel economy. If you`re using the real time trims as a crutch for poor tuning you`ll find big parts of your fuel map will "drift" causing you to re-tune.

As you say the only benifit to running simulated o2 into the ECU is to save money on new sensors.

[Overboosted]

Originally Posted by keithmac

Most people pull the narrowbands to stop the ECU trimming at all (all trims stay at 100%) and wrecking/ fighting the tune.

Running simulated narrowband into the Mitsu ECU will be no better/ more accurate than GOOD stock narrowband sensors, the ECU is still just looking for the 0.5V crossover point.

I pulled the stock o2 and it allows me to run much leaner at some points in the map than stoich, benifitting fuel economy. If you`re using the real time trims as a crutch for poor tuning you`ll find big parts of your fuel map will "drift" causing you to re-tune.

As you say the only benifit to running simulated o2 into the ECU is to save money on new sensors.

That defenently makes sence, I'm glad you understood my post as I wasent 100% sure how to word it . Maybe I will see what I can do with the wideband alone and take it from there.

So what mpg do you get running a bit leaner city driving? My last fill got me 15.2 mpg. That was 2 hours of highway driving (to and from the track), 4 track passes and the rest city driving. IMO thats not to bad.

edit* Also if anyone has any idea how I might be able to fix my load richening tune feel free to say. I asked once before but the only responses I got was to change my setup and I'm not going to do that

[keithmac]

I haven`t worked it out recently but I`ll take some notes when I fill up. I do short 2 or 3 mile journeys most of the week so that kills the economy warming the car up.

Some points in my map where the car would target 14.7:1 I`ve leaned it into the 16`s with no drivability issues, I have total control over all parts of the fuel map now.

I probably spent 4 times longer tuning the off-boost parts of the map than the load areas, it takes some time to get right with 450`s so you may find you have to use closed loop to pull the 720`s into line.

Maybe the SAFC will run out of scope for the fine tuning?, I tune by manifold pressure on a 16X16 load/rpm table and it needs to be that detailed to get a good tune all over really.