mx5cartalk.com

Anyone have any advice? I have NB & just had Xforce headers, hi flow cat & Magnaflow resonator & exhaust fitted last week.

Aside from driving back to Newie & quick run to get new tyres on Monday, she hasn't been out.

Looking to do Grafton run with the club tomorrow & engine management light has come on!!!

Does anyone have any ideas?????

I have disconnected the battery & it has gone but I don't want to fry the motor by just ignoring it



Helen

Did you hook up EGR to those headers?

Or else maybe someone didn't connect the O2 sensor back up properly after fitting the headers (or else damaged the wires). The O2 sensor is a plug screwed into one of the header pipes a little downstream from the engine with a 4 wire lead coming out of it.

Your car should have an OBDII diagnostic port. OBDII scanners are pretty common. Virtually all auto workshops have them. Find someone with one and plug it in to read the engine fault codes. There should be a code there that explains why the light has been on.

there is a threaded bung? off the headers pointing towards the cabin that doesn't have anything attached to it. all the photos we've found of the x-force headers show a cable connected to this but there is no cables hanging down that look like they have wiggled off the thread...
They were fitted by Mania but of course this has happened tonight - so can't ask them for help
Helen

I have just taken her out again for a quick hard run & the light has stayed off

O2 sensors look like this. The end with all the holes in it sits inside the header pipe.

Check for damage where the wires exit the sensor and for a loose plug connection at the top. Otherwise it's back to the OBDII fault codes.

maybe the O2 sensor wire touched the exhaust burnt the insilation and short the O2 sensor. My NA8 as poorly as it's running ATM has never shown it's ECU light. Maybe the tnew headers have been fitted with the O2 sensor in a different position. I lengthened my wire with no probs and the exhaust guys checked the sensor for open closed loop ect... and all was good for me.

Glad to see another girl here

BTW I think 03 models have two O2 sensors, the front one in the headers and the rear one out of the catalytic converter, which is roughly below the front of the passenger seat. Both would have been disturbed in a header change. Same comments about wiring apply to both. If you're getting an intermittent fault then a faulty connection at a plug is a good bet.

Definitely not saying the O2 sensors are the only thing which can trip an engine light, just that since both have been played with then they're probably the most likely. Still worth checking all plugs and leads around the passenger side of the engine bay.

Thanks everyone for the advice
I have been reassured that I have no issues with the car Thanks Mania for the call on the long weekend, it's really appreciated (& certainly wasn't expected)
Have still been having a blast but I can relax now...had already decided on more upgrades if something was wrong...maybe go that way anyway

I had the same problem when I had the exhaust system changed and I kept having to go back to Mania to scrub the code.

The NB8B/C has two sensors so are apparently a bit more sensitive. It stopped Shen I installed an oil catch can. I guess getting rid of that bit of oil vapor recirculating helped.

Ok, we checked all the connections etc last night and all is nice and solid. It doesnt look like theres any loose connection issues there and looks like a really top quality job. (cables mounted up away from the pipe etc)
As the CEL light only seems to be coming on at high revs (correct me if im wrong there Helen) it clearly seems to me like it is the HiFlow Cat not converting the gasses appropriately and the post cat sensor is detecting an "error" (would still like to get a scanner check to make sure we are chasing the right thing)

So what does everyone else do that have put a hiflow cat/full exhuast/headers on their NB?

Is there an aftermarket o2 sensor that has a wider tolerance suited for hiflow cats? or is that calculated at the ECU?
Googling around theres the "antifouling" kits which move the sensor out of the direct gas flow and have their own little filter to clean the air before the sensor. Are these any good or a scam? Has anyone had any experience with these?
Or can the post cat sensor be "bridged" to show it as always being within the tolerances for the factory ECU?

josh wrote:(would still like to get a scanner check to make sure we are chasing the right thing)

In the absence of any obvious wiring faults then you're probably chasing shadows until you do this.

Scanners are less than $20 and run off bluetooth to Androids and PCs or USB to PCs.
http://www.ebay.com.au/itm/ELM327-V1-5- ... a40&_uhb=1
http://www.ebay.com.au/itm/V1-5-ELM327- ... df0&_uhb=1

Looks like the EGR is not connected (the brass plate on the other side has been welded closed) & the intake on the X force headers is also blanked.
Reading other forums, this could cause issues for rego (potentially) & if I come across an interested knowledgeable policeman
Should I get the installers to have it all fitted back up (excuse the ignorance but detailed engine knowledge is not something I have & wasn't aware that this would be removed, until CEL has reared it's head)?
I'm ordering/waiting on OBDII scanner now & looking at fitting an oil catch can
Helen

So the scanner picked up "post cat sensor below threshold".

So question for people with hi flow exhausts, whats the fix? Has anyone here tried the spacer trick?

Seems like a lot of the guys in the U.S use them but not much in Aus from googling