Is it normal to disconnect your battery and then reconnect. then start it up and it idles like crap until you give it more gas. If you let it idle on its own it dies??

Oh yeah CEL light came on when I had my filter out

 

If you disconnect the battery, the ECU has to relearn things... so you will need to let it idle for 15-20 min to do that.

 

^x2 Ibtl

 

Yes, when I replaced my battery, my car idled horribly. I would have to give it gas for it to be able to stay running. Just let it idle for awhile till it normals out.

 

no I don't think that is normal at all. I have disconnected batteries on probably 1 couple hundred cars and never had that problem. Are the connections tight? Which terminal did you put on first? You may have blown a fuse.

 

I actually found out the problem....$278 dollars later. F'n Weapon R Intake! It lets in so much air (unfiltered). I threw a P0103 code this morning, had to take it to Toyota cause the nearest Autozone so I can get a free scan was 20 miles away. I couldn't push the car cause it would go
limp at any gear...I guess the sensor was making it too rich cause it couldn't detect air? Anyway, $100 for the diagnosis freakin robbed. it was in fact the MAF sensor, I refused to pay 160 for the part when its seriously 60 on eBay. got mass air flow sensor CRC cleaner, didn't work.
It must have been beyond dirty that it screwed the sensor totally. Bought the part finally and they wanted to charge 80 for the labor!! So I just did it myself in the parking lot with my tools for 5 mins. Disconnect the battery for 10 mins. restarted let idle for 10 and no Check Engine.
What a pain!!

Note: Clean your Sensor and Intake regularly...don't over oil your filter!

 

man that sucks. All that and the intake doesn't even make you go faster just makes noise

 

This would not cause the idle problem. This could cause your CEL - but the idle problem is because like I said, the ECU has to relearn after the battery has been disconnected.

 

ack154, you don't think a MAF sensor would mess up an idle? Sorry man but disconnecting a battery will not cause a car to idle so bad it dies.

 

It will. It has for me. I replaced the battery and the idle was absolutely horrible. It was the only thing wrong with the car. It fixed itself after I let it run for awhile. I literally had to give the car gas for it to not die on me.

 

Yes... it will. For the tC anyway. I'm not speaking of any other car. Just the tC. Go disconnect your battery for a minute or two and then connect it again - start it and see what happens. Trust me on this.

As for the MAF and bad idle - typically with the tC if the MAF is bad, it will run normal but you'll get a CEL. There could potentially be driveability problems, but more often than not, it runs totally normal.

 

Um, few things that I read here, first the car can run like crap after battery is taken out the loop, it needs to relearn,
second, don't run car with Intake and no filter, third do not oil the filter ever.....that is all.

 

Very true.

Resetting the ECU (aka disconnecting the battery) WILL make it idle very poorly, sometimes to the point of dying when you let off the throttle quickly with the clutch in coming to a stop. And many OBDII cars will exhibit this to some degree, some more than others.
Driving around a bit will clear it up. Perfectly normal.

The Weapon R doesn't "let in so much unfiltered air" unless you don't install it correctly. As a matter of fact, they do little to nothing (all CAI's or SRI's for this car) and will not cause any running issue at all. And if you run an SRI, run a dry filter, not an oiled one.
It is very easy to over-oil them and cause a dirty MAF, which will cause a running issue. SRI's just pull in hotter air than stock.. CAI's do a tiny bit better job of pulling in cool air on this car.. but since most are a crappy metal tube they heat soak worse than stock.
In other words... just a pretty looking noise maker for the most part.