Check Engine Light and Codes

PO422 = Cat inefficiency bank 1
PO432 = Cat inefficiency bank 2
P1119 = O2 bank 2, sensor 1

I would start with a swap of the O2 sensors.

 

Hyperflows, despite what the manufacturer tells you, will throw 0422 and 0432 codes. The solution is to go back to stock cats, or to buy 2 inch long O2 extenders for the rear sensors. Can't tell you what 1119 is.

 

I have hyperflows and the O2 extenders. I do not get the CEL, but will see the codes pending more often than not.

 

+1. I don't even think you need 2" extenders...1" is probably fine. The Motronic is pretty sensitive, seems only oem cats will not throw cat efficiency codes in my experience.

 

I have the 1" version....Will 2" ones even fit?

 

Install the extenders they are cheap.If you keep running with the check engine light on you may not know when your engine might throw a new code thinking its only the old o/2 sensor codes.Make sure your O/2 sensors are in the right plugs and not mixed up. very easy to mix them up if your check engine light came on after major.

 

I put hyperflows on and have logged about 2000 miles and no cat efficiency codes. Installed new O2 sensors all around and added the ground wire to the rear sensors as well. No extenders. Just fyi

 

I've been having the same problem. Every day I get P0432. I researched this and the consensus is to replace the O2 sensors first.

 

It's cheaper than a new catalyst, but ultimately, the cat is probably toast. I went through a bunch of them while I owned my 355...the best ones for the 355 are the OEM metallic ones that Ferrari used from 1999 model year. If you order replacements, I believe that is what they provide. Into the early 2000s, they were still using new old stock ceramic catalysts for warranty replacements on 355s, but those are (finally) all gone now.

I think it was Mark at FoS that suggested the failure point for the ceramic ones is the engine pulses...and the fact the ceramic cores were not secured properly...so they come loose, and crumble, causing the CE light.

If you need a left side one, I have a low mileage oem ceramic one available for sale (less than 12k miles).
If need right side, I have a rebuilt right side, with a metallic core, but like the Hyperflows, it will throw a CE light without an O2 sensor extender (included). It is also for sale. Looks stock, with the original housing reused. Just has some weld seams where it was cut open and welded back up.

 

P1119 = O2 sensor heater circuit (upstream catalyst)(bank 2, sensor 1)

 

Which most likely is a bad O2 sensor...but can also be a bad connector or wiring.

 

True that.

I would swap the O2's from side to side and see if the code jumps.

As for the cats below thresh hold, I wonder if his coolant temps are too low? It may be time for a new thermostat in addition to new cats.

 

No, this is a known issue with hyperflow cats. They throw low efficient CEL

 

First thing to do is to unplug the offending O2 sensor and check the impedance of its heat element with a VOM. But the bad thing here is that you are getting cat efficiency codes on both sides.

The O2 sensor problem would effect fuel trim and could potentially lead to a cat problem. But the thing is the cat monitors should not be running if the O2 sensor is bad. The cat codes will not effect how the car runs. They are just telling you that the down stream O2 sensors are seeing the same O2 variation in the exhaust as the up stream sensors. That is, the cats are not doing their job. Extenders may defeat the CEL but that won't make the cats work correctly.

I've posted this before but I think this is a must down load and read if you want to understand OBD II function circa 1998. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CEEQFjAA&url=http%3A%2F%2Fwww.lbcc.edu%2Fattc%2Fdocuments%2FOBD2.pdf&ei=CXb0U6_oE8K3yASujoDICA&usg=AFQjCNH4CJiyZXgPIvYpDRrIkjG93uaU2w&bvm=bv.73231344,d.aWw

 

As said here earlier. New Hyperflow cats, new 02 sensors all around, GROUND WIRES added, no extenders , 2000 miles on new cats , no cat efficiency codes.

 

Got hyperflows and a capristo and no cat (02) codes ever. Not to dispute the OP's account, of course he is having this problem but as said so do stock cats. These 02 sensors are cheap generic Bosch 02's used in hundreds of models of cars, just replace them, then if you need extenders do that next.

 

Let's see if we can go at this pragmatically.

Question 1: Was there are time after the Hyper Flow cats were installed when the car ran correctly with out CELs?

 

Any idea where I can buy a scanner from to go self checks on my 1996 355?


Sent from my iPhone using Tapatalk

 

Search OBDII scanner

 

Amazon

 

Don't mean to derail the thread but regarding these O2 sensor "extenders" I have a question.

I understand that the purpose of them is to remove the sensor somewhat from the exhaust stream so that the sensor detects less, thereby "fooling" the ecu that everything is good.

But if the O2 sensor is relied on by the ECU, and the data collected is used to perform engine management functions, wouldn't tampering with the data lead to the engine not running optimally?

 

Short answer. Yes