I need to run lean!

[eclipsyco]

Hi guys I'm going to smog test on Friday and I need to make the car run leaner just to pass emissions I probably need a catalytic converter but I don't want to buy it since I'm doing a 2.5 exhaust swap without cat converter just a straight pipe. My co levels are a little higher than they should on idle so what I need to adjust with dsmlink to be just a notch leaner at the moment of the test after the test i'm going back to what I was. Any advice? I have searched all over the internet for an answer

 

[92AWDHX40]

Do you have a wideband?

 

[Travisgsx96]

Ok if your going to do this be incredibly careful if you make the car run to lean you can blow your motor easily which will run you a lot more than just buying the cat. The only way is to adjust your fuel through a Dsm link. If you search for smog tricking tips you can find a lot. One is to silicone your rear o2 sensor so that your front reads the exhaust and the rear does not so it assumes there is a cat on the car

 

[eclipsyco]

Yes guys I know it's not recommended to do this it's going to be only for 10 min max 15 min then I'm switching back to what I was my wideband when idle bounces between 15.x and 14.x I have stock fuel system and stock 2g maf just the cat converter is dead so i need to adjust to be a little leaner just for the test like 16.x or 17.x so what do I need to adjust? The dead time? What?

 

[chadillac2820]

Retard your timing a degree or 2 at idle. That will lower co but raise hc's so don't adjust too much.

 

[GSLENK]

its not a simple adjustment. Your target AFRs, Maf-comp etc only occur during OPEN LOOP. During closed loop, your car will hunt for 14.7 unless something is wrong. That means under load only. You can lock your car into open loop to be sure you are being tested as you wish. and you will probably fry your engine. I dont want to go lean for a second, or knock once. you want to go a full 10-15 minutes? WTF

Good Luck

 

[eclipsyco]

I understand the concern I don't want to run lean either but first of all I'm on 91 octane gas so a lil leaner condition will not hurt me hc levels are good maybe I'll try to retard the timing hope it works I'll try it tonight to se what happens and BTW locking in open loop will make the car run richer not lean

 

[eclipsyco]

Just so you know guys I passed the test and without a cat. Finally peace in mind

 

[hotrodssnova]

Good job. I have an inspection myself in 2 months. How did you do it? Your info will help others out when they do a search.

 

[eclipsyco]

Well... I don't know if it will work for you but all a did was to get lower octane gas like 88 and set my minimum rpm with DSMlink to 500 so it barely stays alive. I was really low on gas so I just added a gallon of 88oct gas drive really slow no boosting and stuff. Now why I use 88oct? Actually I post about this a couple weeks ago, it is pretty simple is just an equation that gives you the proper AFR depending on the gas used, so if the car is always aiming for the 14.7:1 then the 88oct is the gas to use but that's ONLY for idle and/or cruise I really don't recommend 88oct on a turbo car and boosting, the gas will pre combust and you will get some bad knocks. Hope this helps

 

[RacintheReaper]

I'm thankful i dont have to mess with all that . My car would be a disaster to make emissions compliant.