O2 sensor replacement

RuralMX · Post by **RuralMX** » Wed Nov 10, 2010 8:24 am

Hi All,

I am currently looking at why our 98 1.8 NB MX5 lacks power or stumbles easily right off idle til it hits about 1500rpm, like its WAY rich. By 2000 rpm its pulling just fine. I havent had the chance to try anyone elses MX to see if this is normal but i wouldnt think that to be the case. The exhaust is also very sooty (and the back of the car gets soot over it quite quickly) but not wet sooty so its not burning oil.
Above 1500rpm it runs nicely albeit a full tank of gas only get about 400 km's and thats rather sedate driving.
Thus far i've checked the air filter is clean, pulled off the MAF and sprayed it with contact cleaner, checked for intake leaks etc but found none. Theres no issue with the CEL coming on at all either.
My next option was to look at replacing the O2 sensors and was wondering is there a good aftermarket one that will just 'work' or is the best option the genuine mazda?

Also, while i think about it does anyone know a decent tuner in Tauranga (or hamilton/rotorua if I have to) as i'd prefer someone who knows his stuff. I'm pretty sure the performance of our car can be improved on what it is now, not thats its poor but i'm sure it's not running the best it can.

Anyway, if anyone has any suggestions they would be greatly appreciated.

Paul

sprsta · Post by **sprsta** » Wed Nov 10, 2010 4:48 pm

these guys can help with servicing in hamilton

http://www.autowayservices.co.nz/AboutUs

SLYDIT · Post by **SLYDIT** » Sun Nov 14, 2010 9:57 pm

does your car have extractors fitted?

RuralMX · Post by **RuralMX** » Mon Nov 15, 2010 8:45 am

Hey there Slydit,

I believe the exhaust manifold is the stock item. The stock heat sheild is there and the O2 sensor is exactly where diagrams show it should be on the stock system.

The rest of the exhaust is as follows:

CAT > resonator > Mazdaspeed rear muffler

Stevo · Post by **Stevo** » Tue Nov 16, 2010 5:50 pm

Rural MX.
Love the colour of your car......... And the city you live in...... lol.
Cheers Stevo

RuralMX · Post by **RuralMX** » Wed Nov 17, 2010 7:08 am

Hey Stevo,

Lol thanks!
I see you also have good taste in your car colour and city

Paul

SLYDIT · Post by **SLYDIT** » Thu Nov 18, 2010 8:02 pm

ok cool.
just asking as many extractors place the 02 sensor down by the gearbox, and they cool down too much at idle and light load giving bad running lumpy idle, and poor fuel economy..(they need the HOT exhaust gas to keep them operating correctly.)
if you ever fit extractors to an mx5 you MUST fit a heated O2 sensor so it runs correctly.

mobymidge · Post by **mobymidge** » Tue Dec 14, 2010 9:15 pm

Where can I buy a heated O2 sensor from and roughly how much $$?

Euen · Post by **Euen** » Wed Dec 15, 2010 1:28 pm

I paid about $150 for a Bosch one about 5 years ago. Got it from Automasters on New North Rd in Auckland.

O2 sensor replacement

O2 sensor replacement

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