cat removed new problem

I punched out my catalytic converter and reinstalled the downpipe with new rear o2 for wideband gauge. no exhaust leaks i can hear or feel. After driving 15-20 miles finally get the p0420 code but also got a p0171 lean code. right before i got the code my father said there was black smoke coming out the tail pipes. black smoke and a lean code are complete opposites... any ideas what would cause this? i changed the front o2 about 10k ago also

Seeing as you car is newer than most, it runs a different cat check/rear o2 fueling that the older cars.

Not having a cat and being not tuned for it are going to make the car act all sorts of funny and you'll seee that blakc out the tail pipe and terrible gas mileage.

Sounds like how its acting.. didn't know there was anything to tune other than the code being deleted

do you have an o2 emulator?

No don't think those will work on mine

Originally Posted by Fivefingerdeathpunch

Seeing as you car is newer than most, it runs a different cat check/rear o2 fueling that the older cars.

Not having a cat and being not tuned for it are going to make the car act all sorts of funny and you'll seee that blakc out the tail pipe and terrible gas mileage.

I agree kinda I have a 05 Impala SS L67/l32 3"catless dp rear o2 emulator and I set the rear o2 codes to no error report with my HPTuners but I agree I think we need a tune with the emulator and the rear 02 codes being tossed but this just makes the check engine light not come on or a dtc pop up you`ll be fine but if you really want the dp to work on are cars I believe we have to tune.

Your Impala SS a regular SS like mine with a l67/l32 or the Indy EDT with the L32?

Originally Posted by scotty455

No don't think those will work on mine

They will I`m running 1 with problems
with the cat gone it'll dump fuel checking for the cat and run rich its the cat diagnostics test. My ltft's will stay positive and climb higher sometimes and sometimes fluncuate into the negatives its usually the first crank while it's getting up to operating temps.

I`m experiecing this in my 05 Impala SS Series 2 L67, with my 3" catless DP with rear o2 delete & o2 emulator. I dont need to waste money on a $700 4HR dyno tune with HPTuners Pro when it cant get rid of the cat diagnostics, I also have HPTuners standard though it is also a lose since it cant help remove the cat diagnostics test. Is there any other way I can get around this I dont wanna run ****ty like this with slight KR here and there its annoying and im wasting 93+ thats not cool. I think I might just bolt the factory dp up and leave the grocery grabber alone.

I`ve noticed my LTFT`s going crazy and I have read about the Cat Diagnostics Test on 04+ years. I have a 05 Impala SS with the same problem as the others with yall running rich and sometimes slight KR here and there. I am wondering if there is a way around this and if I can get any help, I dont wanna waste my money on a tune with HPTuners Pro when it will get no where. I also have HPTuners standard but thats useless also, well not useless but for this purpose of deleting the Cat Diagnostics Test system then yes its kinda useless from what i`ve read. Can anyone help me with this please.

If you find out, let me know. I needed my CAT or EGR test to complete (but it wouldn't complete due to a high flo cat and deleted EGR) to get my car inspected and I couldn't find anyone that could tune around either.

Just find someone close with a dhp and tiny tuner. If u were close we could kill it for ya

Install a rear O2 sensor with a defouler.

Pretty cheap.

Originally Posted by Z34Phoenix

Just find someone close with a dhp and tiny tuner. If u were close we could kill it for ya

Thanks and I can download TT, also get dhp to run with TT and hopefully delete that cat diagnostics test for good! Is there no other way to rid the dreaded cat diagnostics test? How far are yall or you? Anywhere not to far from Charleston, SC?

Originally Posted by matt5112

Install a rear O2 sensor with a defouler.

Pretty cheap.

Does that even work, my 3" catless dp with no o2 bung your saying drill/tap the dp weld bung on then plug a o2 in. Well I have a new rear o2 sensor but no bung or defouler is what I think is a o2 extension, correct me if im wrong don't know what a defouler is? But will this still work? I was told the Cat Diagnostics Test was so smart, that it would notice the values if the rear o2 bung with rear o2 sensor along with the defouler it would still not work because the pcm would not see the same values, hence the only way to rid the problem is deleting the cat diagnostic test and no other way.

Originally Posted by KeithGTP03

If you find out, let me know. I needed my CAT or EGR test to complete (but it wouldn't complete due to a high flo cat and deleted EGR) to get my car inspected and I couldn't find anyone that could tune around either.

I will as soon as I hear back at someone from over at HPTuners & maybe someone from the forum.

Right.

So were you also told that you couldnt solve your problem by running a cat?

This wont cause kr.

Originally Posted by Overboost101

I will as soon as I hear back at someone from over at HPTuners & maybe someone from the forum.

I talked with the tuners around here (reputable), and there was nothing they could do.

Nope never heard, but if I order another dp with cat it'll always be better then factory cat. So wouldn't the hi Flo catted dp do the same thing, even if I got the dp with the bung for my o2 wouldn't the car still read my rear o2 again and still give me the same problem because the signals between the o2's and pcm would be off, and the pcm would notice the different cat and still give me the same problem of running rich and causes my ltft's to go crazy and stay +.