extractors and o2 sensor changes

G'day lads

Has anyone ever made o2 sensor related changes in their tune, after having extractors fitted? In particular with an na v8 (bf xr8)

Since changing from factory manifolds to Pacemaker tri-y's and more recently, changing those to Hurricane 4 into 1's, I've had a "semi rough" idle and when codes come up, it's always p0133 and p0153 (circuit response slow). Bumping the desired idle rpm up to 650ish helps but I can still feel it isn't as smooth as it should be. I'm guessing the location of the bungs is considerably back from where the factory ones are, moreso with the hurricanes and am wondering if the computer needs a delay or bias adjustment for the o2's to suit?

Other than the dodgy idle, performance seems fine. The car was tuned by a shop when the pacemeakers went in but I can see from comparison to a stock xr8 file, o2 stuff was not altered.

Any advice much appreciated.

Cheers

Slow response codes are very common codes with long tube 4 into 1 headers. Just disable those codes.

Russ Kemp

Hey Russ

Thanks for that tip mate. I've since read some other threads on here in the GM section and see what you mean, it does seem very common.

What is it that's causing the codes in your experience? Lack of temperature or velocity?

Have you tryed 02 sensor extensions? Only way i could clear the p0156 codes on my landcruiser after putting extractors and high flow cats on the landcruiser.

Hey mate

I have them anyway as the hurricane extractors have the bungs further back so the factory sensor wire isn't long enough. The problem is related to what Russ said, in particular it is Transport Delay that needs to be changed in the tune. I haven't cracked it yet.

Increase the transport delay due to the relocation further down stream. Check the fuel trims.

G'day 4wheelin - I did do that initially but "felt" no improvement. I only notice the slight engine shakiness at idle (550 ish rpm) but the lowest rpm value in that table is 700 from memory. I take that to mean delay won't be changed for any rpm below that.

I'm assuming Ford Oz have turned off the other TD settings for self learning as the rpm values in those fields are all the opposite of what I would expect to see.

Cheers mate

Quote:

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Originally Posted by government mule

G'day 4wheelin - I did do that initially but "felt" no improvement. I only notice the slight engine shakiness at idle (550 ish rpm) but the lowest rpm value in that table is 700 from memory. I take that to mean delay won't be changed for any rpm below that.

I'm assuming Ford Oz have turned off the other TD settings for self learning as the rpm values in those fields are all the opposite of what I would expect to see.

Cheers mate

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Can you log transport delay?

hey 4wheelie, sorry mate I have not been on here for some time. Last I looked, there was no way to log that. Since your last post, I have fucked around with a number of those TD settings, despite the fact the factory cal seems to have them all effectively disabled. It didn't seem to cause any problems but nor did it improve things. Given they are mainly to do with learning, I did leave it for a 1000 or more ks so I'd expect that would be long enough?

I have for the time being changed it back and just bumped the idle up to 700ish which offsets the 550 shakiness pretty well.