Celica Forums General Discussion Engine and Performance CAI air too cold?

So I got another check engine light the other day...the first two were both for the need of a new catalytic converter.

This time they said "you were going 74 and the air coming in was 51 degrees. Catalyst system efficiency below threshold. 02 sensor detected lean condition. Cold air intake system may be causing this condition. Tightened clamp on air intake at throttle body (oops). Reset light - may come back on."

This cost me $70. Grumble.

Did you get the code? From the sound of it, it may be caused by a bad O2 sensor or cat (P0420). If it was from running lean (P0171), then yes, it was caused by the CAI. Not because the air was too cold, but because the CAI was designed improperly. The MAFS isn't getting the correct air temp and flow readings because of this, so the ECU can only compensate so much. After that point, it throws a CEL to prevent engine damage.

Was getting P420 CEL Code for 6 months (and exhaust started smelling like ammonia/Lysol toward the last 3 weeks) - Frontier Toyota in Valencia California replaced the o2 sensors and cat under TOyota's 6 year/70k miles emissions warenty...

No questions asked... they just did it


Job was done under 5 hours and haven't received a CEL since...

.

you want cold air. Every drop in 10 degrees yeilds 1 hp.

I live less than a minute from Frontier

I have driven my car in winter with intake on, when its like 0 degrees, never had that problem. However I don't have a CAI I have a short horn? Would that make it less likely to happen? I'm confused...

Code was P0420. I've already had the cats replaced twice, under warranty, over the past two years. The first was before I installed the CAI.

I have also driven in freezing temperatures with my CAI and had no problems, but that was what it was sounding like the guy was trying to blame the problem on; cold air.

What I wrote in the first post was verbatim what the Toyota dealership wrote on my receipt for what they did about the CEL.

So yeah, I'm not sure what to think. Hopefully them tightening the clamp at the throttlebody will fix this problem. It has not come back on yet.

If it's not the cat, then it's the O2 sensors, most likely the one before the cat.

I'll keep that in mind if it lights up again, thanks.

isnt cold air good?

Yes, the colder the better. Colder air = denser air = more power.

had aem cai on my previous car...

when i first got my celica i had a mechanic at the toyota garage tell me that cold air intakes are bad for the engine in the winter time.

would you interpret that as pertaining to the super cold winter air, like 0 degrees, entering cai acting like a constant 5-shot of nitrous?

so is too much cold too much? not all of us live in socal or florida...

e

No problems here with a CAI for two years. Not even a sputter. A 5 shot of nitrous wouldn't hurt any car except one on its last leg. As long as the fuel system can compensate, it's perfectly safe.

i don't know, i was just trying to rationalize what the mechanic said. perhaps the 3% chance of the reduction of engine reliability was what prompted him to tell me that.

I think the mechanic is referring to the problem of cold starts, but shouldn't have a problem as long as your fuel and ignition/electrical systems are good

only way to make sure that wont happen again is to buy a Power FC