going from a4 to a1 crap

[boorishid]

Ok if i go get a cat for a non ulev car and a header for a noulev car and run regualar o2 sensors will the ulev ecu freak out? If i go to a non ulev ecu and do this will i fail smog inspections. Partially asking becuase are o2 sensors are a rip and when i do custom work i dont want to have to worry about the pipes and other things fitting or not fitting my special o2 sensors. What a waste of time and a way to steal your money. blah i hate ulev.

One of my ideas when swapping trannys is to get an a1 manual ecu so thats where im seeing some of these problems come into play with the special o2 sensors, that cost 300 dollars.

 

[HondaLuver83]

You cannot cross anything. The only thing you can do is find a Ulev manual ecu when you do your swap.

 

[lithiumus]

+1 either all ULEV or all non-ULEV (ECU and O2 sensors). The cat is probably fine either way you go.

 

[JMillerUA6]

Cat is different on the ULEV IIRC.

 

[lithiumus]

I would think that if anything, the Cat on the ULEV would be "more" effective rather than "less" effective and the O2 bung sizes are standard. I don't have imperical data on this but ULEV is supposed to be 50% less fuel emitting than regular current models so the cat can only be "more" effective (in theory).

One of the ULEV provisions is that the cat must have quicker effectiveness from the start of the drive cycle i.e. it must heat up and be at full functionality much faster than normal cats. I believe that would be main difference in the cat.

 

[boorishid]

I was under the impression that ulex o2 sensors were physically longer or something becuase there wideband? I remmber reading somewhere a guy bought autozone accord sensors and they didnt fit his ulev model and he then posted a link to some that fit are car on amazon for about 100 cheaper.

As i said im asking for two reasons. #1 Im kind of wondering if when you get emmessions done in california they hook your car to the sniffer. Well is it making sure your immisions are inline with a non ulev car and having ulev just makes it all the more cleaner? and #2 if i buy an ecu for an a1 i dont want it freakin out on the wideband sensors, i dunno if this will be an issue or not? And acually #3 im afraid even though illegal if i were to put like a hi flow cat on, the ulev o2 sensor wont fit? Or if i ran a test pipe with a mechanical sensor emulator i definately dont think it will fit becuase the seansor is longer.

Does anyone acually know of any good technical recources about ulev? The haynes manual doesnt really say ****.

 

[HondaLuver83]

All you need to do is bolt on your stock cat during emissions testing. Hook up a o2 fouler on ur test pipe. Relocate the bung if needed. Easy

 

[boorishid]

Well i understand that but as far as an ecu goes im prolly gonna end up with an a1 manual ecu so i need to know how to make it not freak out with the ulev stuff, and also if i do a full a1 conversion wether that will still pass since my car is vined as an a4

 

[HondaLuver83]

Well i understand that but as far as an ecu goes im prolly gonna end up with an a1 manual ecu so i need to know how to make it not freak out with the ulev stuff, and also if i do a full a1 conversion wether that will still pass since my car is vined as an a4

I don't know for sure the wire harness is even the same, but it doesnt even matter. Your going to have to replace both O2 sensors for a F23A1. Its not even worth it, just buy the ULEV ecu.

 

[Marshall98]

i did a swap from an a1 to an ulev, the ecu is the same. i didint run into any problems