o2 codes

[tappet]

Hey guys,
I have been building a Hilux burnout/show car for the past 12 months.
Its painted to perfection and in my opinion the most awesome Hilux I have ever seen. I dropped the 1uz in with a hi rise manifold so the throttle body is out of the bonnet. Its mated to a ford c4 auto with 3500 stall. Not running timing belt covers and only running alternator, power steering is Astra electric hydraulic works great plumbed straight into Hilux steering box.
Today I did the first start up, nervously pressed the start button, as I have never built anything like this before and bang it fired up instantly, revs like hell and idles perfectly. I know without this forum I could never have accomplished this. So thanks to everybody involved in it.
Just one question though,
After multiple starts now and running it the only codes coming up are the four o2 sensors. When I pulled this 1uz out of the Lexus the two o2 sensors after the cats were joined to the sensors before the cats. So now I am only running the two sensors in the manifolds. Before I get too involved in this can somebody tell me if being a burnout car and the motor getting thrashed if I can ignore these codes or should I rectify this. If it needs rectifying could somebody point me in the right direction to start.
I have to head interstate now but when I get back in about a week I will put a video of the car up.
Cheers

 

[George_R]

disconnect all 4 sensors's wires from everything they are connected to
Then the mixture will be always safe unless something fails (MAF, water temp sensor, injectors, etc)

 

[tappet]

disconnect all 4 sensors's wires from everything they are connected to
Then the mixture will be always safe unless something fails (MAF, water temp sensor, injectors, etc)

If it is that simple, that's great.
Cheers.

 

[tappet]

The Hilux is finished and I recently won a trophy in a car show. It goes insane and with straight through pipes sounds awesome hitting the limiter. I have been trying to put photos and videos up for ages but have had no luck. I'll keep trying.

 

[George_R]

Get yourself a young secretary with SLR and a tablet hehe

 

[tappet]

Get yourself a young secretary with SLR and a tablet hehe

Got it sorted, a pic and vid is now on my low boost thread.
By the way I disconnected the o2 sensors as you suggested and one more code then come up. Code 25 running lean.
I assumed this is what would be expected and ignored this code.
Sound ok?

 

[George_R]

Not good.
My advice was based on my experience with vvt engines

There, a total of 8 obd2 codes must be seen for the setup I described previously: 4 for signal circuits, and 4 for heater circuits. That corresponds to 4 DTCs as seen on the warning light ( b/c signal and heater "extended" error codes, seen with a scanner, are combined into single "simplified" code that can be observed as warning light blink).

If you only observe DTC25, that means:
1 you have some difference in wiring between bank1 and bank2 , b/c lean condition is registered for only one of them
and
2 the ECU did not detect that one of the primary o2 sensors is disconnected. Instead, it assumes that the sensor is connected and is reading lean. ECU then enriched the mixture to the maximum +20% and still observes lean condition on its input

Key point about fixing the issue is to find out the difference between bank1 and bank2 . In other words, find out what's going on on both primary o2 sensor inputs of ECU

 

[tappet]

Not good.
My advice was based on my experience with vvt engines

There, a total of 8 obd2 codes must be seen for the setup I described previously: 4 for signal circuits, and 4 for heater circuits. That corresponds to 4 DTCs as seen on the warning light ( b/c signal and heater "extended" error codes, seen with a scanner, are combined into single "simplified" code that can be observed as warning light blink).

If you only observe DTC25, that means:
1 you have some difference in wiring between bank1 and bank2 , b/c lean condition is registered for only one of them
and
2 the ECU did not detect that one of the primary o2 sensors is disconnected. Instead, it assumes that the sensor is connected and is reading lean. ECU then enriched the mixture to the maximum +20% and still observes lean condition on its input

Key point about fixing the issue is to find out the difference between bank1 and bank2 . In other words, find out what's going on on both primary o2 sensor inputs of ECU

Cheers mate, I will check it out.

 

[tappet]

Sorry for the delay responding, I have been away.
Please bear with me as electronics is not my forte. Sorry George I realise I was not clear with my explanation for what is happening.
Codes 21, 27, 28, 29 are coming up which are o2 sensors which I am guessing are fine as I have no sensors and the wires are disconnected. Code 25 is also coming up which as you know says its running lean.
I run the car in its first burnout comp a couple days ago, did a cracker burnout for its first run which I will put a video up for you to see, but at the end of the run a chap come up to me and said he could hear it was running lean. This scared the shit out of me so I did no more runs. I need to sort this so any help would be appreciated. I am also running a cheap ebay external fuel pump could it cause it to throw a code?

 

[George_R]

ECU can only tell "reach" or "lean" based on O2 sensors
The lack of sensors may have fooled your ECU

Run PRIMARY sensors and forget about the subs, that's safe

 

[tappet]

When the engine is idling it smells rich and fumy, but running at full throttle for a few minutes I was told it sounds like its running lean.
Maybe I have two problems ;
1- The ecu having trouble because of no o2 sensors.
2- Not enough fuel pressure at full throttle.
I will fit a fuel pressure gauge and see what happens.

 

[George_R]

Very probably

 

[tappet]

Thanks George, I will check fuel pressure before I do anything.