OBD1 OR OBD2?

[LoudLT1]

what do i have? i have a 95 Z28 camaro.
why are people doing OBD2 to OBD1 conversionS?
thanks.
eddie

[Jeff_in_Atl]

You have an OBD1 with a bastardized OBD2 connector.

[HottestZ28]

95 was the year gm started to convert to obd2, by 96 all vehicles had to be OBD2
you could have obd1 with an obd2 connector, or obd2 you could easily tell if you look at your y-pipe you would have a post cat O2 sensor if you have obd2

The reason they convert I am not toally sure on other then you can remove rear o2 sensors. there has to be more to it then that though.

[Rob B (shoebox)]

what do i have? i have a 95 Z28 camaro.
why are people doing OBD2 to OBD1 conversionS?
thanks.
eddie

All 1995 LT1 f-body cars are OBD-I.
One reason people convert from II to I is because the programming software is much cheaper. Another is because they don't like all the extra monitoring functions (and trouble codes) used by OBD-II.

[LoudLT1]

thanks for making sence out of that for me guys...
eddie

[Injuneer]

95 was the year gm started to convert to obd2, by 96 all vehicles had to be OBD2
you could have obd1 with an obd2 connector, or obd2 you could easily tell if you look at your y-pipe you would have a post cat O2 sensor if you have obd2

The reason they convert I am not toally sure on other then you can remove rear o2 sensors. there has to be more to it then that though.

There were NO OBD-II 1995 F-Bodys produced. We've been going over this for the last 12 years..... its getting old.

96/97 owners "convert" because there are less emissions diagnostics to get in the way of tuning, and the OBD-I tuning software is significantly less expensive than OBD-II tuning software. Unfortunately, the OBD-I has a problem with shifting on high stall converters, that is not present in the OBD-II PCM's, but there is a work-around.

[Jeffs Black 97 Formula A4]

Actually, I thought the later 95 Camaros were OBDII only in California when the Z28's started getting dual cats. Also worth mentioning if you have a 96+ ODBII car as a daily driver, you must keep it OBDII or it will automatically fail inspection, no matter how clean your exhaust is. Most if not all inspection stations need to see the OBDII funtion properly.

[Rob B (shoebox)]

Actually, I thought the later 95 Camaros were OBDII only in California when the Z28's started getting dual cats. Also worth mentioning if you have a 96+ ODBII car as a daily driver, you must keep it OBDII or it will automatically fail inspection, no matter how clean your exhaust is. Most if not all inspection stations need to see the OBDII funtion properly.

The above misconception is what Fred is referring to. All 1995 LT1 f-body cars were OBD-I, period.

http://shbox.com/1/4th_gen_tech2.html#how_many_cats

[Joe 1320]

Actually, I thought the later 95 Camaros were OBDII only in California when the Z28's started getting dual cats. .

The only 95s that got dual cats was California cars, they were still OBDI but with an OBDII diagnostic port. 96 and later cars all got dual cats and were OBDII.

[ryan34]

So how did the 95 dual-cat cars get 10 extra hp, is it because of the cats? Is this also how the 96-97 cars got the extra hp boost? I just thought that an extra cat would rob hp.

[Rob B (shoebox)]

So how did the 95 dual-cat cars get 10 extra hp, is it because of the cats? Is this also how the 96-97 cars got the extra hp boost? I just thought that an extra cat would rob hp.

They didn't. Their advertised HP was the same as the single cat cars.

It's funny...on another board people contend that the two cats gave it the the extra 10 HP.

[ryan34]

They didn't. Their advertised HP was the same as the single cat cars.

It's funny...on another board people contend that the two cats gave it the the extra 10 HP.

So what about the 96-97's? I think they are advertised at 10 extra right? If so what gives them that boost? Or is it just that, advertised .

[Joe 1320]

Here's the deal........

The 96 and later dual cat cars have a revised Y pipe that sends each bank of cylinders into it's own dedicated cat. Due to a slight decrease in back pressure along with some tuning aspects, the OBDII dual cat cars got a boost of 10 HP.

[ryan34]

Here's the deal........

The 96 and later dual cat cars have a revised Y pipe that sends each bank of cylinders into it's own dedicated cat. Due to a slight decrease in back pressure along with some tuning aspects, the OBDII dual cat cars got a boost of 10 HP.

Ahh...thanks joe, i was just seeing if it would be worth to do whatever the 96-97 cars had to my car....but it sounds like headers would take care of it.