ECU Errors

[the_random_hero]

I'm about to make up a SRI to fit a newer Aurion/TRD Aurion, some people have reported that a dash error light will go off. Trying to see if this would happen, I had a friend move the top of his airbox (in essense creating the same flow that a decent pod filter would have), he started the car up and ran it for a few minutes, no error lights at all. I'm not sure if his car is just different or it has to be under load, but I would prefer to have a sort of definite answer before I go spending money on some good quality alloy bends.
I know some Camry's, Mazda 3's and various other cars definitely throw an error light and I'm looking to know why. Is it due to the MAF sensor reading excess airflow and assuming there's a problem with the intake path, or is it due to turbulence in the airflow (both I've been told are the cause). Another reason I'm confused is a few people do a CAI for the cars mentioned, and this doesn't appear to set off any errors (even though the intake path is only a couple of feet longer).

[SuperDave]

The consensus for the Celica giving an error light was down to the MAFS being mounted too close to a bend or the throttle body. This would be down to turbulance confusing the MAFS, so it would read normal volume, suddenly read a low volume, then suddenly read a high volume for example.
Another problem the Celica had was going to a 3" pipe, the Corolla was fine with the 3" pipe due to the above mentioned MAFS positioning. So I assume a similar theory would apply to the Aurion.

[the_random_hero]

Hmmm, interesting.Has anybody else got any input/experience? Apparently Aurions don't like you changing the exhaust at all either...

[the_random_hero]

Nobody else has any input?

[the_random_hero]

Nobody else has any input?

[JetspeedCamry]

Well an engine will only consume what it needs. You can't give it excess airflow by having an open filter or anything. I'd say that theres some sort of sensor in the airbox (the intake air temp sensor) that perhaps is reading incorrectly or isn't plugged in. Other then that, there should be no difference between them (apart from the heatsoaking and dirty filter syndrome )

[JP]

I've made one for a TRD Aurion, the ECU logged a MAF code almost immediately but the car still ran, can't recall what code it was now though... was probably an airflow low code. It DID require a scantool to clear the code though, pulling EFI fuses etc wouldn't clear it.

The intake I made was identical with regard to internal diameter and sensor element height compared to the factory airbox. The transition on the one I made was fairly close to the end of the straight pipe so there wasn't much space to develop any laminar flow.

When I get some time I'll be changing the design and placing additional straight pipe prior to the MAF placement. If you look at the underside of the Aurion airbox prior to the MAF, the MAF isn't THAT far back from the end of the plastic tube it lives in.

You can weld "airflow" straighteners into the maf housing prior to the element which can also help if you're experiencing turbulence around the MAF. Plenty of pics around the web of this, especially on the CNC machined 3" housings used on celica's, WRX's, suzuki's and basically anything else that uses the Denso hotwire style maf. The aurion uses the same style maf as the MY08 onwards subaru's with a different airflow scale.

BTW, it's REALLY easy to make a TRD aurion throw a CEL, as you've already been told on other forums their ECU is quite sensitive.

[Brad-KE35]

I just came

[JetspeedCamry]

I just came

LOL.

That's a nice donk for sure!

[the_random_hero]

I've made one for a TRD Aurion, the ECU logged a MAF code almost immediately but the car still ran, can't recall what code it was now though... was probably an airflow low code. It DID require a scantool to clear the code though, pulling EFI fuses etc wouldn't clear it.

The intake I made was identical with regard to internal diameter and sensor element height compared to the factory airbox. The transition on the one I made was fairly close to the end of the straight pipe so there wasn't much space to develop any laminar flow.

When I get some time I'll be changing the design and placing additional straight pipe prior to the MAF placement. If you look at the underside of the Aurion airbox prior to the MAF, the MAF isn't THAT far back from the end of the plastic tube it lives in.

You can weld "airflow" straighteners into the maf housing prior to the element which can also help if you're experiencing turbulence around the MAF. Plenty of pics around the web of this, especially on the CNC machined 3" housings used on celica's, WRX's, suzuki's and basically anything else that uses the Denso hotwire style maf. The aurion uses the same style maf as the MY08 onwards subaru's with a different airflow scale.

BTW, it's REALLY easy to make a TRD aurion throw a CEL, as you've already been told on other forums their ECU is quite sensitive.

Thanks a lot for the information! Was it you that posted in a thread I was reading over on TOCAU? I'm hoping one of the four or so cars that have volunteered to be a victim...uhhh test subject have a Scantool to clear the error. I might just do some experimenting and see if I can make something work.
I was also thinking about one of those "idle stabilisers". If it's due to turbulence, then it could possibly be a solution.