Engine issues

Hey there.
Long time...

I am having issues with my car, I think it may be O2 sensor related.

It's been so long I can't remember what sensors I rendered useless.
Isn't it typical to render the front two out of the tune?
also, which colour cable is that, blue or green?


Second question.
My issue started after I washed under the hood. The car runs perfect WOT however idles like crap. What engine management system turns off at WOT? Knock sensors can, O2 sensors, what else?

explict said:

Isn't it typical to render the front two out of the tune?

Click to expand...

My tunes have always been written with the rears off

Okay, yeah its been a while.. ill look upon what colour the rear is

The rear O2 sensors are disabled in the tune if you're running a catless exhaust. The ECU goes into open loop and ignores the front O2 sensors when you go WOT, so it seems that at least one of those sensor wiring harness connectors may have been contaminated with water. You might want to inspect them, clean, and apply dielectric grease.

Correct. Front are monitors. Rears are generally turned off.

No codes? How does it run otherwise? Does it only run good at WOT? What about light or half throttle? Accelerate OK? A little vague on the issue. I mean first thing I would say is to clean your TB, Motion Plates if you have them and your MAF sensor. Then I would say unplug your coils one by one and see if the motor idles the same or not. Then do the same with injectors. Start with the basics, air, fuel, spark.

Check the coils as well and make sure there is no water under the boots as well.

The rear o2 sensor connectors are blue I'm pretty sure. Go over the plug boots, and I'd replace them if they've never been done. And check to make sure plugs are tightly seated.

Since it happened I replaced cops, alternator, MAF sensor and o2 sensors. Mostly upgrades but. It had a code o2 sensor stuck open which is why I replaceded them. Never fixed issue. Almost like it's upstream from the sensor.

Wot it'll lay strips, but idling and slight accel it lags, it stutters, it's crap.

Another riddle.
Why do I have a connector extension that changes from green shape to blue shape?

???

need more details

I had a factory green o2 sensor connector plugged I to an extension but the extension changed to fit a blue o2 sensor.

Supplementary question.
Are all o2 sensors the same?
If a green connector is plugged into a blue o2 sensor is it okay? Or are one more sensitive than the other?

blue is the rears, green is the front iirc?
but im not 100% if they are actually different or the same and just different connector colors

The front O2 sensors are different than the rear sensors.

+1 the green connector sensors are fronts, blues are for rears. The fronts switch fast, the rears do not.

Stop looking at connectors and color coding if the problem started after you washed the engine. TF people?
Pull the codes and report back.
Also, sounds like you have O2 extensions for long tube headers.

I mentioned plugs and COP boots in my post. Those areas can be affected after washing the engine.

O2 extensions are normally for the rear but some like myself have used them up front. The sensors are the same they just have different connectors. If you cut the tabs on the front sensors you can plug them into the extensions. That is why you have two different colors on the connections. As long as you have them going to the right spots it really doesn't matter.

Check the vacuum with a gauge. Depending on how "gently" you washed, may have something not tight or positioned just right.