They wanted me to pull the ECU from the car and send it to them...and any adjustement would need to be done the same way, so that was that, no way...

 

Hanging around eurocharged open-house on more than one occasion, I did observe them having to physically remove ECU's out of some vehicles, and perform to modify them / flash them on the bench...

 

If anyone is curious to follow. I am in the process of having Jerry tune my car with a 3lb pulley and PSE ported blower installed. I think one thing people are forgetting is that the OP has a car with over 100k miles on it and presumably the original supercharger. The unit could be slightly worn out and not producing peak performance. In addition, the car had stock exhaust if I am not mistaking. I feel that the magnaflow cats made a substantial in how the car breathes (coming from worn out factory cats with 45k miles). And the sound is much much better.

So anyway, lots of cobra guys used to port these things if they didn't have money to upgrade to a KB Blower. so I am hoping with a PSE complete reman and port it will make a slightly larger gain than the original poster.

My mods are as follows:

Intake elbow
Magnaflow spun cats
PSE ported and reman'd M112 w/ 3lb Mina gallery pulley
Mina rear boxes & magnaflow center x-pipe
Eurocharged ECU tune

 

Eh, exhaust was custom 2.5" header back, with generic high flow cats, into a mina-gallery axle-back, so eh, not totally stock...

I later did an all new exhaust setup with 2.5" stainless manifold back, cat delete (with resonators in their place), H-pipe, stock resonator, and mina gallery axle-back.

I've since updated this setup, to delete the two resonators I put in place of the cats, and it's now "straight-pipe" from the manifold back in 2.5" stainless.

I'm planning another trip to the same dyno soon to see if the exhaust work/cat delete netted any gains...

I agree, my STR has about 100k, and could be pretty tired, so the output may be lower than expected, but who knows, every dyno reads differently, point is, there was a "10-15whp" gain from the Eurocharged tune, so if your STR is putting out marginally more power, an EC tune could net 15-20whp maybe? I wouldn't expect this car to gain 40+ from this tune, so the gains I made I think are pretty good... the fact it isnt worthless vapourware, is pretty awesome because so little 'tune' options are available for these cars to begin with...

 

Cat delete?

From the pics it looks like you've put minicats on the downstream O2 sensors to keep the CEL / codes away? I'm surprised Eurocharged did not include turning off the cat monitoring in their tune.

We recently found out that using minicats is not a good solution, better to turn off the catalyst efficiency monitoring instead, since the downstream O2 sensors are also used for fuelling.

Have a look in this thread https://www.jaguarforums.com/forum/x...0/#post1211413 particularly at the AFR curve before & after. We didn't change anything except for remove the minicats & turn off the cat efficiency monitoring.

 

Cambo... What you see in the photos was my exhaust setup last year... Those "mini-cats" are actually just straight-through resonators, not cats. I put them there for two reasons. One, attenuate exhaust noise from deleting the cats, two, to have the visual appearance of cats still installed.

I've since removed these resonators, and it is now just straight 2.5" stainless piping from the exhaust manifolds back...

Interesting info on secondary o2's effecting fuel trim.

I too was surprised the Eurocharged tune didn't disable the secondary o2's to begin with, but at the time of the flash, I still had cats in place, so it wasn't really on my mind... I've since returned to Eurocharged (canada), and asked if they could re-flash my STR to disable the secondary o2's, now that I've done the exhaust revisions.

The local EC rep told me he would have to contact Jerry in Houston first to find out, and get back to me, but I haven't heard back yet...

I'll also add... From the time I deleted my cats, in order to avoid a CEL due to P0420 cat efficiency, I left the secondary o2's plugged in, but not inserted into the exhaust.

This prevented any CEL lights due to cat efficiency, but my "emissions readiness monitor", under the "oxygen sensor" category, would read permanently "NOT READY", probably why it never did show a cat efficiency code.

Anyhow, since then, I've re-installed the secondary o2's into the cat-less exhaust, albeit, with 'extenders' on them, to draw them slightly out of the direct exhaust stream. The monitor immediately went "READY" afterwards, and no CEL either, so that much is good...

 

By "minicats" I meant the extensions that bring the O2 sensors out of the exhaust stream, they have a small catalyst honeycomb in them. Usually the extensions alone aren't enough to stop the CEL & codes from being set, guess you've gotten lucky with just the extensions.

Yeah it's a fairly new realisation about the downstream O2 sensors being used to manage the fueling. TBH it probably has little influence on the maximum power, but as you can see in the other thread, the AFRs and the consumption improvement in regular driving, there is a difference. Taking the sensors out of the exhaust stream or tricking them messes the closed loop fueling and it goes rich to be "safe"

I've done the same ECU adjustment on my XJR when the 100 cell cats were installed, it now gets the best fuel consumption I've ever had and you can see the difference in the tailpipes, they used to soot up, now they are clean.

 

On early OBD II systems, the post catalytic converter O2 sensor has no effect on fuel control. The post catalytic O2 sensor was originally responsible for only monitoring catalytic converter efficiency.

Stating around model year 1999, a new type of converter came on the market, called “Low Oxygen Storage Converter” or LOC. With an LOC, the pre and post O2 sensors cycle at the same rate. These converters are tested by measuring the lag-time between the two signals. A further development of this system is that the post converter signal is also used for A/F correction, but to a less extent.

 

Eh, I wouldn't say I got lucky... the o2 extenders on the secondaries is a VERY common and well documented mod to prevent the P0420 codes from appearing, I've done it on other cars, and the internet has plenty of anecdotal evidence to suggest its plenty effective...

I remember monitoring live date through OBD, that the system would still go into closed loop, despite my secondaries just reading free-air... Furthermore, I also noticed my instant fuel economy reading when cruising at highway speeds to still read about 7-8L/100km steady... so I don't think it was running much richer to be honest, or preventing it from going into closed loop, but after reading that thread you linked to, I'm sure there WAS some marginal difference to fueling made due to how the o2 sensors were reading free-air / readiness monitor in a NOT READY state... Although knowing what I do now about secondary o2 operation, I would do more datalogging in the future to gather a better idea how the whole system responds to these sort of tweaks...

As mentioned, I've since plugged them back into the exhaust stream, with extenders, and all is well, passed an emissions test yesterday, etc...

I can say since returning the o2's back into the exhaust stream, I feel I get slightly more popping/gurgling coming from the exhaust than before...

Hope a future eurocharged flash will rid me of the o2's all together...


I plan to do the spark plugs soon, transmission service, and return to the dyno this season to see where the car stands now with the new exhaust setup...

 

Well, I for one never knew that. So, a question...

I am about to replace the OEM cats on my '05 STR with a Magnaflow 99675 and include a Magnaflow 11385 X-pipe. Also got new before-and-after O2 sensors and extenders, to try and prevent CEL errors.

What effect might those extenders have on the ECU's ability to control A/F ratios?

 

Yep, and when the downstream sensors aren't responding, as they are out of the exhaust stream, the ECU takes a "default" action because the measurements from the upstream and downstream don't correlate.

Some first hand experience; Sid's XJ from the other thread was fitted with extenders on the downstream sensors when the cats were done, the CEL / codes kept coming back, it wasn't until the minicats were fitted on the downstream sensors that the codes stayed away. Talking with the guys who put my cats on, they said this happens a lot with "Euros" and the minicats are the solution, or turning off the codes in the ECU completely.

Yeah it still goes closed loop, but it's "closed-loop + safety factor" if you get my meaning.

Steady cruise at 110kmh on level road sees 6-7L/100km instant on mine now, and over a 15km run on the motorway the short-term average was 6.4L/100km (reset once at speed)

More telling is the normal traffic figures, it's come down from ~16L/100km to ~13L/100km

You can't get rid of the the downstream sensors, they have to be plugged in and measuring correctly. Turning off the Catalyst Efficiency Monitoring just means it will never throw the codes. The sensors are still needed for the closed-loop AFRs

Putting an extendor on an upstream sensor will definitely throw your fueling off. Why would you put them on the upstream sensor?

 

Plugged in, sure, but I was picking eurocharged' brain about this, and different cars have varying degrees of flexibility with their software insomuch as it related tuning out the secondary o2's... thanks Lobb

I agree, with the secondary o2's disabled or not ready, the ecu likely 'looks up' another table for some small safety modifier... Good to have a better understanding of how the two sets of o2 sensors inter-function for cat efficiency calculations...

Having my emissions readiness monitors read READY, with no CEL's, and pass a modern emissions test, means I'm plenty satisfied for nnow. Car is straight-piped, yet still very quiet cruising, no drone at all, better crackle and pops, def worth it...

 

Sorry for the confusion, by the plural "extenders" I meant one left and one right, on downstream sensors.

So, what effect might those extenders have on the ECU's ability to control A/F ratios?

 

Can only confirm that also on the older cars like mine the ECU is also using the downstream o2 sensors to regulate the fuelling. I found this out as one wasn't functioning properly, causing one bank to have a different fuel trim, which gave an uneven wot situation, where 1 bank was leaner than the other.

Not sure what the effect can be, the 1st thing that comes to mind is that fuelling adjustments will be slower to react as the narrow band ones are quick in responding and I guess less quick once you use these type of extenders.

I am about to install my own O2 sensors, and the manual mentions that I should measure before the cats, as otherwise you could get a leaner measurement. Considering this I would guess that with the extenders the downstream o2 sensors might read more lean, which could mean the ECU will enrich the mixture somewhat. But if there is an effect and by how much, and than the effect on wot is something you need to measure carefully.

 

You can see the dyno graphs in the other thread I linked to, with the extenders/minicats fitted the AFR has a very unusual curve, likely due to the sensors responding too slowly. The curve with them removed looks "normal".

It's quite clear the extenders/minicats make the closed loop fueling rich. The fuel consumption figures and the state of the tailpipes (greatly reduced soot) with them removed leaves no doubt in my mind.

If the tuner knows what he's doing then it should be possible to change the settings as part of the tune. But you don't need an aftermarket tune to turn off the catalyst efficiency monitoring, it can be done with IDS/SDD. However you do need to access Engineering Mode to edit the vehicle configuration, which is very complicated and you need to know exactly what you are doing.

MoscowLeaper did it remotely using my IDS/SDD & MongoosePro cable via Teamviewer, messing with the 1's & 0's is well over my head....

 

Interesting posts! Maybe I should delay fitting extenders until I see whether or not the Magnaflow cats give a CEL.

Maybe I'm having a dumb day. Don't understand the value of the LOC technology once the cat is less than 100% efficient which, in the eyes of Jaguar, would be the case when an OEM cat is replaced with a 200-cell version.

 

Back to tuning options! I have an 07 STR with Mina pulley, Mina cat-back exhaust, & Caldoofy intake tube with K&N drop in. I Emailed a few companies on tuning and thought I had a deal set with Eurocharged. They were supposed to mail me a tool to plug in my ECU and read it. Mail it back to them. They tweak the tune and mail it back to me to plug back in my car. Then when I called them back to "rent" the tool needed the guy I talked to the second time told me that's not an option for the STR? So now I'm confused. And have called and emailed Eurocharged several times since with no answer or response back. Super frustrating!

 

turning off the post cat o2 sensor isnt going to give you more sluggish fuel response the primary adjustment reference is the pre cat sensor. The secondary sensor is referenced for catalyst protection/emissions efficiency fueling adjustments. It can't be used for primary fueling as the catalyst changes the gas concentrations making the feedback inacurate. you put an extender on it and the ecu sees a lean post cat condition, it knows too lean means more NOX emissions so it throws fuel at it. The logic isn't too hard to grasp.

 

Lobb,

I have read a Jag doc that sated the downstream was used for fueling but sadly I can't find it. This has also been confirmed by dyno tests and someone that knows the programming of the ECU

From what I understand different markets have different emission requirements
The ECU uses this to keep emissions under the market levels.

Fitting a cat with less cells, clearly produces more emissions
The ECU attempts to compensate however if the change is too great it can not do that and you get a CEL.
In other words its running lean

Add an extender and you put this off, lowering the difference between the OEM and aftermarket cat.
This can keep the ECU within limits, stopping the CEL and richens the mixture.
In the case of the SC engines it already too rich so this is not good. Better than lean but still not good

Add a Minicat and you effectively get a much "cleaner" signal to the ecu, making the mix rich as well, possibly richer depending on the length of the extender

You could "tune" the length of the extender to produce a stock mixture but that is a lot of buggering around.
It is far better to turn off the downstream sensors emissions functions.
This leaves the other functions of the ECU in tact for these sensors.

Any way you do it, ECU, Minicats, Extenders the emission will be off and you wont pass a test.

For us here in OZ that's not an issue.
The big fines are for no cats ($50,000) not ones that don't pass ($300)

This is the reason Cambo, myself and other have 100 cel cats fitted and not a cat delete

Cheers
34by151

 

All modern cars use the post cat o2 for fueling adjustment related to emissions, it's not exclusive to Jag. But it has limited influence only about 20-30 percent over the total range