Guys, I'm getting the following codes from the ECU on a 97 355 Spider: P1448 - Catalyst bypass flap circuit - malfunction P1451 - Secondary air pump circuit - short to ground Does anyone know what to look for or what could be causing this problem? Thanks, Chris
Is your exhaust bypass valve opening or not? Is it stuck open? Does your car "resonate" when driving slow around town? That could be a stuck open condition..... Stuck close? Car exhaust is fairly quiet and you do NOT get that WAAAAAA sound when agressive on the throttle? (like when you use to open up the air cleaner on the old carburator...if you are old enough to remember) The EXHAUST bypass valve opens via vacuum, based on a solonoid valve which opens which I believe is based on the ECU. The exhaust bypass valve is located in the exhaust. You can see it under the air intakes. This valve is closed at rest and opens around 3000 RPM based on a few different parameters. The solonoid valve is located on the passenger side in the rear right behind the back bumper. In my 1997 the vacuum line which connects from the solonid valve to the hard metal tube was disconnected. This small hard tube is attached (welded?) to some framework in front of the air cleaner assemblies on the passenger side. You really can't see it from the top and from underneath you must look VEERRYY CLOSELY as it gets lost in all the vacuum line plumbing. My guess is the dealer who did the 30,000 mile service (previous owner) forgot to attach the vacuum line. I never knew it was not working until I checked it. I only checked it because I read about it here on FerrariChat. Once I attached it I got some great sounds out of the exhaust which I never had before. And in my "feel" (maybe it is just the sound) it does feel more free flowing (more power). For your information, I never did get a check engine light but I did have a "pending" P1448. Once I attached the vacuum line, I cleared the code and so far it has not come back. I hope this helps.
Great info!! I will check out my vac lines tonight! Apparently my CEL went on with that code P1448 last night after some spirited driving. I will be working out every small bug that arises. I hope to be code free soon!!
Thanks for the Info. The only thing I found was the clamp on the hose that connects to the bypass was a bit loose. After some more driving I'll see if this works. Thanks
How does one check to see if this valve is geting electrical power? I think my exhaust bypass valve is not opening. The engine does not sound very loud when on the throttle anymore. Not to mention I just got CEL w/ code P1448. I checked all the vacuum lines and they are all good. Do these go bad often? The Ricambi part # (159177 VALVE/SOLENOID) I was thinking of running a check valve inline so that if my bypass valve DOES open, it would not be able to close. That way I can get out of the car and see for myself if it is working. I checked the actual bypass valve and it does work. So now it is just a matter of the solenoid either getting power or not working alltogether. Any input or experience with this is requested... =~) Image Unavailable, Please Login
I am now DTC free in my 1997 F355 spider! I replaced vacuum lines, installed kingsborne wires, sealed a split in the potting of one vescovini ECU, lubricated the soleniods for the bypass valve/cold start valve, replaced the thermal switch on the LH radiator, pulled apart o2 & temp sensor connectors everywhere & put contact/anti corrosion lube on them and thats what it took!! Now over 150 miles later, even with some very spirited driving and not one code!! In the past I would get P1448-bypass, P1445-vescovini, P1115-o2 sensor & couple others after only 10 miles or so. Not all at once but sometimes even within a few minutes! So thanks to all who have posted help/info on code issues!! I read all of them and they were instrumental in my troubleshooting endeavors!! !!!