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97-06 Jeep Wrangler TJ ECU / PCM Tuning Options

Rick2004LJ

Member
Jun 11, 2018
53
Texas
I am in Texas in a county (Harris county) that requires Inspections with emissions. If I start messing with deleating emmissions etc. will the Jeep fail inspection? Or since the tune keeps the “check engine” light from coming on will that let it pass inspection?
 

dbbd1

go away...
Supporting Member
Jan 4, 2019
776
Oregon
I guess that it all depends on our they check your vehicle. In Oregon (many moons ago) they used to check with a sniffer tube shoved up our exhaust. They may still for older vehicles that do not have OBB II. All of the vehicles that I have now have OBD II, so they check through that. I know that they are checking for CEL's but also some emissions stuff prints out for them too.

Other states have "safety" inspections, which sounds like it can be a whole other ball of wax...
 

Rick2004LJ

Member
Jun 11, 2018
53
Texas
They don’t do the sniffer, just the OBD port. Maybe it just checks for error codes and the tube cancels them out??
Hopefully someone in Texas has done one of these tunes and knows the answer
 
OP
Chris

Chris

Administrator
Staff Member
Sep 28, 2015
38,127
Salem, Oregon
They don’t do the sniffer, just the OBD port. Maybe it just checks for error codes and the tube cancels them out??
Hopefully someone in Texas has done one of these tunes and knows the answer
I can’t say for sure, but give it a try with the emission systems disabled just to see if it passes. I suspect it will, as there won’t be any present check engine lights.
 

skrelnik

TJ Addict
Supporting Member
Jan 10, 2018
1,090
CT, United States
They don’t do the sniffer, just the OBD port. Maybe it just checks for error codes and the tube cancels them out??
Hopefully someone in Texas has done one of these tunes and knows the answer
You have to be careful as the tune disables the emissions, thus no CEL, but the PCM/ECU may say the emissions system is not ready which could lead to failing the test, depending on how many "not ready's" the state allows, and what your tune shows.

The surefire way is to go back to a stock map before heading into emissions.
 

HarleyMick

Member
Supporting Member
Mar 29, 2019
42
Rock Hill, SC 29730
I just wanted to tell you guys I tried everything I could think of including a Hypertech tuner to keep 'Ronda' from shutting down at 4,500 rpms. Then I read Chris' message about having the ECM re tuned to change things like the rev limiter.

I sent Dave Casper an email yesterday and he called me a couple of hours later. He confirmed everything Chris said and then some! When I told him everything that had been done to the old 4.0 and my chief complaint he asked how many rpms I wanted. I told him 5,500 and he laughed and said there is a lot more in that engine that the ECM is holding back besides rpms. He suggested I send it to him and he would program it to let the engine run the way it was built to. So I paid $399 to B&G Performance/A2Speed online with my Visa and took the ECM to UPS. It's on the way to Michigan and I should have it back in about a week.

I asked Dave to disable all of the limits. I think I'm old enough to know that even with the crank, pistons and rods balanced a crankshaft that long should probably not exceed 6,000 rpm. I've got about 5k in the engine and I don't want to lose it. I'll let you guys know the results of Dave's work.

One more thing. While it may not be prudent for a couple of EPA guys to try to test cars in rural South Carolina, I'm going to buy a stock ECM just to have in a cabinet in my garage. Just in case.
 

Fouledplugs

TJ Addict
Supporting Member
Jun 19, 2017
2,640
Alabama/South Carolina
I just wanted to tell you guys I tried everything I could think of including a Hypertech tuner to keep 'Ronda' from shutting down at 4,500 rpms. Then I read Chris' message about having the ECM re tuned to change things like the rev limiter.

I sent Dave Casper an email yesterday and he called me a couple of hours later. He confirmed everything Chris said and then some! When I told him everything that had been done to the old 4.0 and my chief complaint he asked how many rpms I wanted. I told him 5,500 and he laughed and said there is a lot more in that engine that the ECM is holding back besides rpms. He suggested I send it to him and he would program it to let the engine run the way it was built to. So I paid $399 to B&G Performance/A2Speed online with my Visa and took the ECM to UPS. It's on the way to Michigan and I should have it back in about a week.

I asked Dave to disable all of the limits. I think I'm old enough to know that even with the crank, pistons and rods balanced a crankshaft that long should probably not exceed 6,000 rpm. I've got about 5k in the engine and I don't want to lose it. I'll let you guys know the results of Dave's work.

One more thing. While it may not be prudent for a couple of EPA guys to try to test cars in rural South Carolina, I'm going to buy a stock ECM just to have in a cabinet in my garage. Just in case.
Looking forward to your results. Keep us posted.
 

SumGuy

New Member
May 28, 2019
1
Palm Beach Gardens
Extra points if they can disable that useless, annoying "shift" light. That would be worth the price of admission all by itself. Bugs the crap outta me.
You can pop out the instrument cluster and remove the bulb on some unit unless it the led type. It's fairly easy to do.

Now the real reason I am here. I have a Fake Jeep. AKA 04 Liberty 3.7 4x4 5 speed. I think the engine and trans are the same, but not 100% onit. I want to fool the computer into thinking the cats are inplace. The resistor trick only works for a few days then it goes to running poorly until I reset the ecu again. I want to know if any of these software will fix this issue. I dont want to put the cats back in. They are not cheap, and are the leading cause of head gaskets blown on most cars when cats get old.

I would appreciate any info on this. Thanks
 
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Chris

Chris

Administrator
Staff Member
Sep 28, 2015
38,127
Salem, Oregon
You can pop out the instrument cluster and remove the bulb on some unit unless it the led type. It's fairly easy to do.

Now the real reason I am here. I have a Fake Jeep. AKA 04 Liberty 3.7 4x4 5 speed. I think the engine and trans are the same, but not 100% onit. I want to fool the computer into thinking the cats are inplace. The resistor trick only works for a few days then it goes to running poorly until I reset the ecu again. I want to know if any of these software will fix this issue. I dont want to put the cats back in. They are not cheap, and are the leading cause of head gaskets blown on most cars when cats get old.

I would appreciate any info on this. Thanks
With the software you can disable the post cat O2 sensors, which effectively allows you to remove the cats altogether.

This isn't an opinion, it's a fact. Whether or not it works on the Liberty, I don't know, but I know for sure it works on the 97-06 Wranglers if you use one of these softwares.
 
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Paparock1

Angry SE
Supporting Member
May 14, 2018
112
AL, USA
it was asked above and I didn't see an answer so I will ask again. I assume that this includes the 2.5?

All I have read is the 2.5 is what it is, however now with being able to modify the PCM I would think that us 2.5s could get some mods and tune it now? I mean its still just an air pump right, and now we can adjust for the tweaks?

I personally didn't know much about Jeeps before I bought mine with the 2.5. I thought upgrades would be easy even a simple 4.0 swap would be in the future, but I was wrong. Well I wont say its not that it is hard but it requires more additional replacement of components. I guess that happens with all engine swaps though. I guess what I am trying to say is that its not a 69 - 85 Chevy where you can go from a 258cc all the way to a 400cc without much change.
 

HarleyMick

Member
Supporting Member
Mar 29, 2019
42
Rock Hill, SC 29730
With the software you can disable the post cat O2 sensors, which effectively allows you to remove the cats altogether.

This isn't an opinion, it's a fact. Whether or not it works on the Liberty, I don't know, but I know for sure it works on the 97-06 Wranglers if you use one of these softwares.
Chris, my ECM is on the way back from Dave Casper of B&G Performance. Right before he received it I called and asked him about doing away with the cat and he said it's not a problem as long as I keep the rear O2 sensor intact. I spent a good deal of time yesterday removing the cat, knocking out all of the insides to where it is totally hollow and reinstalling it. I'm also adding a Dynomax ultra - flo muffler that is straight through on the inside with only perforations surrounded by fiberglass.

There will be no limits set by the computer so the 'red line' is up to me. I'm thinking 5,500 with the balanced engine, what say you?
 
OP
Chris

Chris

Administrator
Staff Member
Sep 28, 2015
38,127
Salem, Oregon
Chris, my ECM is on the way back from Dave Casper of B&G Performance. Right before he received it I called and asked him about doing away with the cat and he said it's not a problem as long as I keep the rear O2 sensor intact. I spent a good deal of time yesterday removing the cat, knocking out all of the insides to where it is totally hollow and reinstalling it. I'm also adding a Dynomax ultra - flo muffler that is straight through on the inside with only perforations surrounded by fiberglass.

There will be no limits set by the computer so the 'red line' is up to me. I'm thinking 5,500 with the balanced engine, what say you?
Pshhh... I'd be very cautious about redlines without ARB head studs and stronger connecting rods and such. The 4.0 isn't a big revving engine, and I suspect to make it one, you'd have to do a lot of work. If anyone would be able to answer this with certainty it's Golan. Those guys build tons of high output 4.0s for a living, I'd feel much more comfortable with them giving an answer than me. However, I would say if you raised the redline a few hundred RPMs, you'd likely be fine.

Good to hear about your experience with Dave. For the longest time he must have dropped of the face of the earth. Never returned my calls, emails, or anything.
 

MX952

TJ Enthusiast
Sep 10, 2018
212
Orofino
Chris, my ECM is on the way back from Dave Casper of B&G Performance. Right before he received it I called and asked him about doing away with the cat and he said it's not a problem as long as I keep the rear O2 sensor intact. I spent a good deal of time yesterday removing the cat, knocking out all of the insides to where it is totally hollow and reinstalling it. I'm also adding a Dynomax ultra - flo muffler that is straight through on the inside with only perforations surrounded by fiberglass.

There will be no limits set by the computer so the 'red line' is up to me. I'm thinking 5,500 with the balanced engine, what say you?
Any update on the re-program? I’m thinking I want to have mine done too but curious how it ran.


Sent from my iPhone using Tapatalk
 

HarleyMick

Member
Supporting Member
Mar 29, 2019
42
Rock Hill, SC 29730
Installed and runs great. The rev limiter may have been at 4200 but the re line has always been 5500. When I'm playing I speed shift at 5000. I highly recommend the reprogramming if you don't want the factory restrictions. The ECU comes back with a sticker on it that says 'Off road use only'. Takes about 30 seconds to remove it. No codes either.
 

alquick71

New Member
Jun 12, 2019
1
New York
I’m considering sending out my ecm to B&G Performance to have the post cat sensors written out of the computer. Does anyone know it this will cause the ecm to not finish the monitor for the o2 sensors? I feel like it would stay incomplete, but not 100% sure. I’ve also have been considering the o2 simulator that area 74 provides, but have heard mixed reviews on results. Just looking for the best solution and any advice would be appreciated.
 
OP
Chris

Chris

Administrator
Staff Member
Sep 28, 2015
38,127
Salem, Oregon
I’m considering sending out my ecm to B&G Performance to have the post cat sensors written out of the computer. Does anyone know it this will cause the ecm to not finish the monitor for the o2 sensors? I feel like it would stay incomplete, but not 100% sure. I’ve also have been considering the o2 simulator that area 74 provides, but have heard mixed reviews on results. Just looking for the best solution and any advice would be appreciated.
I don't believe this will be an issue, but it's best to ask Dave at B&G, as he will know for 100% certain.
 

HarleyMick

Member
Supporting Member
Mar 29, 2019
42
Rock Hill, SC 29730
I gutted my catalytic converter so it is totally hollow. I advised Dave prior to reprogramming and he told me I only had to leave the O2 sensors intact. He programmed it for my total setup including disabling the rev limiter and it shows no codes. It also runs great. The redline on the speedometer has always been 5400 anyway.
 

RitualHabitual

TJ Noob
Supporting Member
Extra points if they can disable that useless, annoying "shift" light. That would be worth the price of admission all by itself. Bugs the crap outta me.
I replaced my gas gauge light recently ($17 at my local Chrysler dealer, if I remember correctly). I wish I would have pulled the 'shift' indicator light while I had the instrument panel out--didn't think about it at the time, but seems it would be a workable solution. It is super annoying.