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Secondary air system activating when driving


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The secondary air system on this (2008 2.5XT) failed (in a good way; pump siezed, valves stuck shut) at 40000 miles and I have been happily driving it around on the basis of wiping the error on first start up which normally lasts the whole day, (depending on use/weather sometimes another wipe is required). Just recently (now at 125000 miles) the fault has been occurring whilst driving and generally won't clear. From a cold start it will normally clear; it returns after about 5 minutes driving and then won't clear again except occasionally on very long high speed runs it will clear for a while but then returns. (Suggests something temperature related)? The pre and post cat sensors are all behaving themselves (they are new units) and there is no discernible change in performance (at least not as far as I can tell) and the thing runs like a dream; no misfires etc..

I am at a loss as to what is now causing this demand for the secondary air system when in use; presumably this would be either "low temperature" or "high emissions"? Open to suggestions as to what is causing it; and how to kill whatever is causing it! I am simply looking to get back to the original state of clearing it once a day and getting a few more years (and a few more MOTs out of it).

Thanks in advance for anything you can offer.

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it needs to be turned off in the map, however you want to have the butterflies removed otherwise there is a risk of them getting stuck in the wrong position which afects afr's

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Thanks; I do plan to get these mapped out at some point. Do you have any idea why I would suddenly be getting a demand for the secondary air pump whilst driving - it has never happened in the previous 124000 miles - why now?!

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The secondary air system is pish, put simply. It on;ly works for 30 seconds when the car is cold, so it gets a nice amount of condensation in it, which then builds up and corrodes the insides of it and over time theres your issue. when mine was taken off water litteraly poured out of it. Water + time = issues.

 

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I know this! For the 80000 miles since it failed I have cleared the fault after cold start and it's generally been good (warm) enough to last me to the next cold start - no faults are registered when driving around. Recently I clear it; drive for 5 minutes; fault reappears; won't clear. Clear it on next cold start; drive it for 5 minutes; fault reappears; won't clear.

Something is asking for secondary air to come on whilst I am driving - (if the system hadn't failed I would be in trouble because this thing catches fire if you drive around with it operating - it's an ill wind....). I am trying to find out what/why something is asking for secondary air when the engine is warm......

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