dose any one know what the thread is for the ports on headers? if some one dose im going to start making nice caps for them. (so it looks better then just cutting and crimping the pipe, or welding the hole)

 

I believe its M20, I just used M20 drain plugs from carquest, looks nice to me. But I believe different years had different sizes.

As a side note, anyone keep seeing that J&M ad and have the urge to rush out and buy them? dammit I cant afford it! I'm saving up to goto florida for spring break

 

Does it affect your car to take the AIR pump off? I've heard that it makes your car run lean and you get SES lights is this true?

 

i don't think it does that on OBD-1 cars

 

EGR sort of does this. Your car attempts to open the EGR valve and expects the mixture to richen up wherein it leans it back out, if you disable the egr valve but don't program the code out then when it tries to open it itl'l notice your car is running leaner than I expected, but its no leaner than normal operation its just not as rich as it should be with the EGR open.

 

No it does not. OBD 1 no SES.

 

http://shbox.com/1/Dtcs.htm
Whats code 32 on odb-1 then?

 

On the OBD-I cars, the removing the EGR is a hit or miss. You may or may not get a code. If you do, you'll have to program it out. As for the AIR, as long as you keep a good fuse and an intact electrical circuit, you won't get an SES light as the PCM only checks the integrity of the AIR electrical circuit.

 

Hard to understand how he got so many responses, when he never told us the year of the car, or the brand of the headers??????

What year is your car (stock manifold threads vary by year) and what brand are your headers (some headers do not match the stock fittings, and require adapters)??????

No. Single cat stock manifolds are M22-1.5 oil drain plugs (not exactly, but they fit fine). The dual cat manifolds have a smaller thread (M18???). And the headers may be different, depending on the brand.

No. It won't run lean. Removing the AIR system affects NOTHING, except how long it takes the cats to heat up. The system only operates for 2 or 3 minutes at startup to help the cats heat up. In OBD-I there is no code, in OBD-II there will be.

With respect to AIR in OBD-I, you are 100% correct.

No. If the PCM tries to open the EGR valve, and there is no EGR flow, the O2 sensors will correct for the resulting lean condition. It will continue to operate at 14.7:1 in closed loop, and EGR is not functional in PE mode.


Z28Roxy was talking about the AIR system, not the EGR system. The AIR system wil not set a code if the fuse is still good (OBD-I only). About 80% of the time, because the OBD-I diagnostic is not very sensitive, the code will not set when EGR is deleted.

 

its a 93 Z28 with pacesetter mids.

 

just wondering if a set of pacesetter LT's for a 94 would have the same cap as him? i think i heard they are a m20 cap?

 

My numbers were off I believe Injuneers right that its a M22, and to the guy I posted the link to Im sorry I coulda sworn you were replying to me not the other guy. The plugs i put in did something strange, the first time i put them in a bit of metal came off of them (like he said its not an exact fit). so what I did was I ran em down into the hole, pulled off the metal that peeled off, blew the hole out with air to get the threads clean then wiped copper rtv with my finger around the threads on the plug then tightened em in

 

If your headers are coated, the coating will peel off when you screw the plugs in. It's not the plugs losing metal. The M22 is a "loose fit", compared to the threads on the stock plumbing.

 

kk, do they sell these m22 plugs at local hardware stores (ace hardware), or maybe carquest?

 

They are sold in auto parts stores, particularly the ones that cater to imports.... its the standard drain plug on many years/models BMW and Alfa Romeo. It's also available at Dodge dealers, because that's the drain plug used in the Cummins Diesel. There's a mail-order in Canada that sells them for less than $2, but the shipping is higher than the part cost.