O2 Sensor Codes - 0153, 0159, 0133, 1039

None of these codes are due to the straight pipes. Test pipes should only produce a P0422 and P0423 codes. Sounds like you have Cat ECU and O2 sensor issues.

 

maybe the pre-cat sensors are plugged into the post cat sensor ports (and visa versa). If they were mistakenly plugged in incorrectly then that may cause all 4 O2 codes that you describe.

 

What was your reason for changing the pre-cat sensors? where you getting these codes before you changed the sensors?

 

I suspect your downstream 02 sensors are not detecting enough of a voltage (and therefore oxygen level) difference from your upstream sensors due to the test pipes. Your O2 sensors are likely fine, but your ECU doesn't know you don't have cats.

 

so if you run catless space the the downstream 02 sensors. Do a search I have posted how to do this and with "what" that fits perfectly.

 

Oh, I have read your "kluge" thread several times and am in the process of implementing your solution on my car.

 

Not true. I am personally running decat pipes and only get P0422 and P0423 which are the codes for cat inefficiency. The O2 sensor codes are directly related to the O2 sensors or electrical system somehow. The codes isn't for efficiency, it's for low circuit response. I would start by making sure you have the right sensors and they are connected properly. I got some of these codes years ago and fixed with new O2 sensors. But since all 4 sensors are giving an error, I suspect larger issues. The ecu isn't reading any of the sensors.

 

Yes it is totaly a kluge that works. Unfortunately, on Ferraris running 5.2 motronic and above there are no tuners I know of who can tune the ECU's. So we have to trick the ecu's. You might have read about my SDECU kluge too. On our C5 C6 vettes we have a more elegant and lighter weight solution of removing 02 sensors and tuning them out of the ECU with software. It is amazing what can be tuned on a Vette. Even the vette paddle automatics can be hot tuned to shift at 100ms and hold until the rev limiter comes in. So you can have almost 360 F1 shifting but GM reliability!

 

I don't know what that is or like that design. You need to have the downstream 02 in the stream so that there is a reasonable difference upstream to down stream. The ECU looks for some kind of Delta. If you tkae the DS02 completely out and tie it up under the car that does not work for example. The simple spacers work. Look for the Dorman "HELP" products at the autoparts store. Or google those extenders. I always buy the one that fits the 02 sensor bung, i forget the size, and I have to drill out the inside of the extender with a 5/8 or 1/2" bit through and through and then screw the DS02 right in. Only once did I have to space the sensor a little more out.

 

The 5.2 ECU looks for the front sensor going ever so slightly rich then ever so slightly lean in a periodic cycle, while the rear O2 sensor reads relatively constant (after warmup). The front sensor is used to keep the mixture near stoichiometric, the rear sensor is used to tell if the cat is working.

 

Why did you change the O2(upstrem,primary) sensors?

Don't know where you got the new ones or what type.....put your old ones back in and see if the codes go away...if they were good before and you haven't contaminated them they should work and the only codes you should see are the ones Brendan posted.

It won't be the first time I've seen new out of the box ones bad...they will not produce enough voltage to cause the ecms to go into closed loop. You do not want the car to remain in open loop...it will run rich and that aint good.

If you still get those slow response codes then first and foremost check your wiring especially the connectors...looks can be decieving...that is wwhy they make volt/ohm meters.

I kinda like the little thingies for the post cat O2 sensors but have no experience with them...don't know if they are the culprit but FBB's post is a tried and proven solution.

 

In vette world we also use electronic 02 simulators that send an actual signal to the ECU. I is some voltage iirc that simulates 14.7/1 AF ratio. It is a simple circuit that I have nver bothered to make because the extender works 100% of the time and I'm a manual kind of guy like a caveman with a club. The feds made those people stop making them but you can figure out how to do it with a simple web search.

 

Funny....I'm right there with you on this.

My big weakness is anything that involves electronic gizmo's.....I'm soooo bad I thought "wire nuts" was just another male problem like e.d.

 

A Ferrari F1 or DCT is not in your future either. I might have to go to the darkside which has been calling me....PANZERS! I am resisting with everything I have.

 

What is the exact reference of your pre-cat O2 sensors?

I would guess they are not the OEM sensors for a 5.2. Your codes are consistent with the installation of wrong pre-cat sensors. May be the ones for a 2.7?

 

Yes, the wrong pre-cat sensors will perturb also the reading of the post-cat sensors by the Motronic.

 

Really? If things haven't changed to much atleast their workshop manuals are intelligently written and are accurate...nothing like that italian jibber jabber manual who's accuracy is hit and miss.

Check your 550WSM and see if it has the same bs pertaining to the rear O2 sensors taking over fuel trim in the event of primary O2 sensor out of limits/no signal. You've gotta be kidding...right?

Funny you mention the F1 system, my next car just may be that because of my left knee problems. Atleast I know some people that can help me out in that area..lol

I alked with Bruce this morning.....I asked him a question that maybe you and he can resolve at next weeks get together at Vince's.