Check Engine - No Cats

Guys - i just took the cats off my car and put test pipes on.

I went ahead and spaced out the 2nd O2 sensors, but i've just tripped a CEL.

Code is P0421 - "warm up catalyst below threshhold"

Did I space the sensors too far out? or are they not far out enough?

Thanks, any help is appreciated.

Bobby

 

This is great. I was about to do this same setup. Fabspeed said they can send a extension for the O2 sensor to help trick the computer. But not 100%.

Looking forward to hear inputs.

The dealer did tell me that they tried with one car and they could never figure out hot to avoid the CEL.

 

I think member Ingpr figured this out, he is running test pipes with no codes I believe using an extender--

Hopefully he will add some input or message him

 

The first time I installed my test pipes the cell did pup up. I turned the master switch off overnight and the next day it was gone. Some times when a really push the car hard the light comes back but after storage it goes away. It never turns on at normal driving. I ask Bobby about how far he goes with the extension. After turn on the master switch put the key at start position without start the car and wait until the EUC reads all the maps and settings.

 

subscribed

 

Ingpr - how long are your O2 spacers?

 

It was hard to find it back but I finally found it!
This is the web page I used to built my simulators;
http://www.energeticforum.com/renewable-energy/1387-o2-sensor-modification-using-spark-plug-non-foulers.html

check it and compare.

 

Give me until tomorow and I will take the sensor out and check the lenght of my spacer.

 

David - no need. Just give me an idea... 1/2 inch? 3/4 inch?

I don't want to create any extra work for anyone. I appreciate you helping me though.

All i really need to know is does the p0421 indicate that the spacer is too short? or the spacer is too long? If i can get this answer, i will know how to adjust accordingly.

Thanks again!

 

Bobby already knows this, but for the rest, changing the code in the ECU is the only guaranteed way to avoid the CEL.

 

It also makes a large difference how wide the opening is for the 02 defouler. Mine right now are set at 3/16 of an inch and I haven't gotten a cel.

Certain cars we have to open up and some need a very small hole. I'll get pictures of mine since they are off the car.

 

So why my cell light off?

 

I guess I should have reworded it. You can get the wire in O2 simulators, but they are a hassle. The O2 spacers dont always work, it depends on the vehicle. They usually will, but not always.

 

Bobby,

Check my drawing. (Hey dont mess with my draw! I had to use Paint because my Autocad is on my Office Computer)
Image Unavailable, Please Login

 

Excellent drawing my friend!! Basic - yet effective!!

I'll have a toy with it and let you guys know. Thanks everyone!

Bobby

 

Hmmm... 3/16ths huh? Have you logged a lot of miles? my CEL came on after about 100 miles.

 

Evoms it
Novitec

Who else has ECU rep for 360 or 430 ?

 

Bobby,
After you tunr the master switch on back, do you still had the cell light on?

 

haven't had a chance to check. I will fire it up tonight after work. Will let you know by this evening!!!

Thanks again man.

 

P0421: warm up catalyst below threshold (bank 1). Means it's efficiency percentage is below the allowed window or "threshold".
The fact that the code is for only one bank means theres a variance between the installation of the two sensors. One of the sensors is located in the rear port, the other is now relocated to the rear port also. The sensor is spaced out approx. 1/2-3/4" and is tighly shrouded...should be good now.

 

Good point!!
This question may sound crazy,
Bobby
did you installed the extension only at the last sensor? Or do you installed extension on both sensors at the test pipes? The first sensor is Air/Fuel Ratio and it does not need an extension. Just to be sure and touch base with you.

 

Great thread on discussion with this...If we could keep this one going as a final solution thread & hopefully start talking about "catless" manifold swaps & deletion of that sensor also.. besides the $2000 + or - reflash of ecu,,,

 

http://www.o2simulator.com/doc/Adjustable_o2sim.pdf

 

well that right there would solve the issue of either set of sensors..manifold or cats... just sucks that its bulky hardware that would need to be wired & put somewhere... all though you could hide behind a panel with the other electrics I suppose, ie; behind the seat...

Be worth buying a set of sensors or using the old sensors, cut the ends off near the o2 sensor & fabricate so you can plug directly into the vehicles sensor harness plug...

sure be alot less than 2k +/- to reflash the ecu & still keep the system fairly stable I would imagine.... They list a $85 price... if anyone tries it, please keep us informed.

 

The solution is a proper reflash - and it shouldn't cost $2,000 +/-.

Jim