CAT/Slow Down Light Problems with my F355. THEY WERE REPLACED!!!!

I recently purchased a 1997 F355 with 24,000 miles. Looking into my records the previous owner replaced the cats and ECU at on 2007 and 15,500 miles.

Now here is my issue. After driving the car today, 70 degree day my SLOW DOWN light would blink at speeds of 70mph and over. And, if I went faster the vehicles SLOW DOWN light would stay on for 10-20 seconds and putting the car into "limp" mode of such.

My check engine light came on, when I put the OBD2 Scanner I received the following codes.

PO432: Main Cat Efficiency below thereshold Bank 2
PO1448: Unknown
PO139: 02 circuit slow response Bank 1 Sensor 2
PO133: 02 circuit slow response Bank 1 Sensor 1
PO134: 02 circuit no activity detected Bank 1 Sensor 1
P1119: Unknown
P1446: Unknown

The Vehicle has TUBI exhuast.

Its hard for me to believe the CATS need to be replaced this early in their life. The ECU's were also replaced during the same period when the CATS were done. Both at ALGAR Ferrari.

Any help would be great. THANKS FELLOW OWNERS!

 

I would start first by changing the two O2 sensors on bank 1 (right side).
And, check operation of the bypass valve.
Check the wiring and connectors involved, then reset the car, drive it to see if error codes come back.

 

I would start by agressively cleaning the connections first, reset codes, then see what pops up.

 

+1

 

Is there a diagram or a video that shows how to clean the connections correctly? I am 350 miles away from the closest Ferrari mechanic.

On my former Lamborghini there was a few great websites that showed a full DIY instruction practices for owners to practice.

Any ideas?

 

Also, as my reading I haven't fully diagnosed the problem. Does anybody think this could maybe a problem due to needing header replacement? And if so, is an engine out procedure?

 

+2

 

the pre O2 sensors plug into the wiring harnesses with blue tape.... I would bet the pre and post O2 sonsors are plugged in backwards.. Also be sure The O2 sensors are correct (a simple check, the pre O2 wires are much shorter than the wires on the post O2's)

I had same codes on my OBD II and this was my problem, now everything is ...perfect (for now) LOL, ed

 

your problems are mainly bank 1 (righty side)
be very sure there are no air leaks where the cat connects to header (may need new donut, very inexpensive but I would jack your car up, pull right wheel off and loosen cat and see if you can tighten it up in a non binding position ( sounds easy.. it is not and it is very important to not have any air leak)....... (I have replaced cats by removing exhaust from above, or removing wheel..... removing wheel is much easier !!)

good luck, ed

 

+1, I would start with replacing the O2 sensors (pre and post) on bank 1. BTW, what brand and type of catalysts were installed? Oem or aftermarket?

 

I have been told they are fab speed cats. That is what the previous mechanic said. Is it possible the slow down ECU is faulty? As the problem only happens when the vehicles speed passes 71mph (slow down light blinks, than stays on completely and car goes into limp mode until vehicle is under 70mph again and light doesn't blink or stay on) than when it's below that speed the vehicle is fine? This is quite the mystery.

 

VERIFY THAT YOUR BYPASS IS FUNCTIONING BEFORE DOING ANYTHING ELSE!!!! DO NOT BUY ANY PARTS UNTIL YOU DO!!!

First, pull the bypass plunger...it's just under the vacuum dashpot. It should travel smoothly from closed to open position with about 3 pounds of force. If it works smoothly, it's mechanically okay.

Second, check the presence of vacuum at the dashpot. If necessary, pull the line back to the vacuum tank and inspect it for obstructions.

It has been somewhat popular for technicians without specific Ferrari experience to plug this line in order to even out the idle...not sure where they got this idea.

 

ELC System 2 Fault

Manifold Absolute Temperature Circuit High Input

Evaporative Vac Solenoid Circuit Malfunction

+++++++++++++++++++++++++++++++++++++++

REMARK ---- These are the "generic" OBDII (not necessarily "Ferrari-specific") DTC definitions

 

+3

 

Then after you finish chasing all the ghosts buy the SRI Gold Connector Kit and end your pain forever and then your car can run like Ricks...
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