Re-occurring P1135 engine code on Miata 2000 above 4000 RPM

A good smog test AND repair center that you might know and trust may be
your best bet

Well, I can feel your pain for having a problem. BUT, I can't feel the
the same pain that you have for a "dealer" that somehow people run into.
I live in Seattle WA. One of the dealers we have here is the "First"
dealer for Mazda in the US. I had a head gasket problem on my '91. It
was 1994 and way out of time and milage, but they replaced it. 4 years
(yes 4 years) later, it started to leak again. I took it in and after
they had the car for 2 days, ( a free loaner car to me ) they said that
they would relplace the gasket at no charge. Sooooooo, you see, it is
hard for me to think all dealer service is bad.

I hope you can find a dealer that will treat you well and fix your
problems.


Bruce Bing '03 LS

> GUEST wrote:
> I have replaced the front heated oxygen sensor with a Mazda new
unit to
> fix a fault consistent with the P1135 indicator and I have cleared
the
> engine code/CEL. However, whenever I wind up the engine above 4000
RPMs,
> the engine light, the P1135 code and 2 sensor indicators (whatever
that
> is) come up up again. I have searched the net for equivalent
failure
> modes and I can find some cases when this has occurred, but it
appears
> that people have not posted the subsequent solution. The engine
does not
> run rough at all at any RPM and there is no lost of engine power.
The
> P1135 code is the only one that gets triggered. This is a bit
confusing,
> since other failures associated with the coil, etc. triggered other

> codes in some of the web postings I have read.
>
> Is this an indicator of problems in the VICS, the coil pack, the
> EGR/ducting or what? Unless the new Mazda OEM front O2 sensor is
also
> bad, I think the P1135 indicator is a mis-mapping of some other
fault
> cause.
>
> Thanks for any help or follow on discussion.
>
> Zoom, zoom, zoom. :-\
>
> Roland
> (original owner Miata 2000 SE, 48,000 miles, one year old NGK plugs
and
> cables, good battery, everything else is original)

Rha: I am
currently having the same problem. Just purchased a 2000 Miata
and I got two codes last week, a PO300 and P1135. Fixed the plug
wiring
and no more PO300, but I can't keep the car from showing a P1135 once
I go WOT. It appears to be the same problems you were having back in
'07. I am curious on if you found a final diagnosis, was it a bad
ground? I've replaced the plugs and plug wires. 'm tempted to just
take it in to the miata dealer but will be getting my hands on a jack
next week so I think I'll wait to look at the rear O2 sensor wiring.
Let me know if you have any input. Thanks for your time.