95 Catalytic Converter Questions

[s14junky]

1. Is there only one (front) cat on this model? I heard 95 is a "split" year.
2. If there is only the "front" cat(welded in), what is the cat looking device directly under the drivers seat? Mine is completely hollow but NOT gutted. Was this a factory spool or what?
3. Has anyone ever run a second cat inline with the front cat to beat the smog man? Im hoping to lower my HC reads so I can pass smog. Seems California lowered its smog limits when I wasnt paying attention.

By the way...the front cat is located directly below the exhaust manifold and has both of the vehicles O2 sensors before and after it. I really dont want to have to weld in a NEW CARB cat in that front position.

thanks in advance.

[compactfean]

There aren't any pre cats to my knowledge. (look at the engine family code on you're emissions sticker under your hood and it will tell you) and there are cats that are ”extra loaded” and do help, but cats mainly help with co numbers (running rich) not hc. Sounds to me like you need to look into a complete tune up and dial in tps voltage, idle, and timing.

[s14junky]

Thanks for the input. I already did all that stuff. My HC was 69 ppm, the limit is 62. I brought it down from 80 with the tuneup etc. I also retarded my timing from 20 to 16 btdc. Much to the chagrin of the smog guy. I just read a little more about cats. A properly operating cat should not be emitting much O2 if any. So, if a second cat was fitted inline there would not be enough oxygen to "light off' the rear cat. If thats true, how do inline cat systmes work? Thoughts?

[s14junky]

Upon further research I found that the 95's indeed had a fake or hollow "cat" downstream of the real cat (located near the exhaust manifold). SO... I added a NEW Magnaflow cat in its spot giving me the equivalent of 2 cats inline. No biggy right? The downstream cat "lit off" nicely. About 500 deg. in and about 575 deg. out. I should be able to get this new setup past the smog man easy right?? Well when I got back behind the wheel I found out I had pulled a DTC 25 (P0505) IACV-AAC failure code. Coincidence?? I took the new cat off and put the factory test pipe in and tried to re-set the CEL. NO DICE! There doesnt appear to be any added back pressure , as I have very good exhaust pressure at the muffler tips.
Any thoughts on this ? Maybe its just coincidental and Ill go thru normal troubleshooting. This is starting to bug me.
Any help is appreciated.

[compactfean]

Id say completely coincidental. 2 cats should definately should help though.

[s14junky]

Update: Code P0505 was a pain to fix. Had to pull the IACV-AAC devices off my engine and clean them. I also used some contact cleaner on the EFI connector upon assembly. Not sure which fixed it but the CEL is clear so now its off to the smog man Monday morning.
So if 2 cats inline dont pass smog, Im going to register this car in South Dakota. f*** it.