I recently put a pacesetter header and magna flow highflow cat and about 2 weeks after I put it on check engine light came on had code read was rear o2 sensor causing problems so I ordered o2 simulator light went off for about a week them came back on had code read again no its saying that the cat is not cleaning enough any help would be appriciated its a 2002 z24 with 2.4 would replacing the o2 sensor with a new one fix this problem

I know several people have this header and a high flow cat is anyone else having this problem

o2 sims dont get rid of problems that were potentially there...

in life there really are no cheap fixes for long runs or bandaids for broken legs...

what cat do you have and how old is your rear o2 SENSOR?

the rear o2 sensor is the stock sensor the car has about 47000 miles on it now and the cat is a magna flow high flow cat that I got from [URL=http://www.turbotechracing.com] the first time the light came on it was just the rear o2 sensor throwing the codes the second time the light came on with the o2 simulator in place its saying that there is to much emissions coming out of the cat so I know the o2 simulator isn't working properly I'm just wandering if I replace the o2 sensor with a new one if that will fix the light issue

i have the Pacesetter Header and magnaflow high flo catalytic converter and my PO133 (Front 02 Sensor Code) has gone off many times. I been trying to figure out ways cause i have already replaced the sensor. When it comes on, it says that the sensor in bank 1 is reading to slowly...with this performance header, i could understand that cus its a lot more air flow than the stock exhaust manifold....i think it comes on when your in to high of a gear at lower speeds...it might just be something you have to deal with..when mine comes on, i just discconnect the battery so it resets my ECU untill i get my ECU reflashed when i get my new motor (thanks to jbodyperformance)
hope this helps
01 Z24 Owner
(comming summer of 06- Fully rebuilt NA 2.4 Motor)

Huh strange i have pacesetter header High Flow Cat from Ebay and Dymonax muffler and have never had this issue. I changed both O2 sensors at time of installation.


2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

from what i understand, the simulator is supposed to replace the second o2 sensor to get rid of that specific code.

yeah that was my thoughts also called rksport and they are wanting to know the code that is going off of course its at home and I am at work so I'll call them again tomarrow might just go ahead and replace the o2 sensors and see if that fixes the problem and just forget about the o2 simulator

I have installed a header, high flow cat (magnaflow), and cat-back exhaust. Upon installing the system, the wires for the header sensor were extended, and the cat was placed about 4" back from where the stock cat sat. The sensor for the cat was welded in about 2" after the cat, and have not had any problems at all.......this all went on a 98' sunfire 2.4L........blksunfir

I have done some checking and the best I can figure is that my car is running extremely rich and thats what caused the o2 sensor to burn up so does anybody have any good ideas to solve my problem I was wondering if a msd ignition would help

does anyone have any Ideas on how to get it burning leaner so I can replace my o2 sensor and get the light to go off

Jesse, From looking at the MagnaFlow website I have to ask you which part number
cat did you put on? The cats in our cars are 3-way cats so if you only put on say a 2 way cat then then thats your problem for the second o2 sensor. Did you check there web site before you ordered and see which ones you could use? I'm going with a 93000
series cat from them as they say it works as a 2 OR 3 way cat.

Hope this helps you and after this weekend I'll have mine on and I'll tell you if it works

Good Luck.




Semper Fi SAINT. May you rest in peace.

Ok all the cats from 95 and up are 3 ways from the factory and most aftermarket ones are designed to work on these cars i don't know why your haveing the problem. Other then SOME "high flow" cats don't do enough to clean the exhaust so maybe thats the problem. Just about all cats these days flow like 95% of straight pipe. High flows may reach 99% but it would appear that perhaps they don't do enough. The cat I'm getting is just a plain 2 1/2 inch Magna Flow one And according to there web site is 3 way capable for engines up to 368 cubic inch and vehicles that weigh up to 7000lbs gvw
so I'd say I should be safe but again I'll let you know if I have problems too.




Semper Fi SAINT. May you rest in peace.

dunno if this is off topic, but what about the anti-fouler mod? i forgot the link that was connected to a honda site, but it would stil work on the j-body. just wanted to let you know if this would help. if not then im just sticking my nose and help at the wrong time





*Devil Z*

Ok gotta ask whats the anti-fowler mod?




Semper Fi SAINT. May you rest in peace.

update to it to dealer ship my brother in law works at over the weekend the codes that im throwing is P0420 which is catylist low , a code that means both the o2 sensors are reading rich had o2 simulator on back side of cat thats when the P0420 code first started up reset the computer hooked up the o2 sensor and it came back on again any ideas

do the $5.00 o2 mod. i have no cat on my car and I did this mod and I have not thrown a code. It works like a charm.

well i must have emailed the right person at rksport finally and the are going to send me a new o2 simulator to replace the one that went bad I'll try that out if it works good if not then I'll probably do the anti-fouler thing and give that a try

The rksport o2 sensor are kinda notorious for not working, same for their tach adaptors. Just an FYI.

thanks for the heads up if another one craps out fast i'll try the 5.00 thing and see how it goes

i am having the EXACT same problem as you. only my rear isnt going off, just my front. , bank one sensor one and same code numbers. i bought a new o2 sensor, everyones telling me that this should cure it, we'll find out tommorow...

well i got my exhaust leaks fixed, and my new o2 sensor. everythings cleared and fine for now, but we'll see what happens. i give it two months.

finally got the new o2 simulator in today installed it and changed out the o2 sensor in the header so far so good no codes and seems to be running much better not running as rich now and also had the battery disconnected for about 45 minutes I guess I'll see how long the new simulator lasts