05 Lexus GX 470 codes, idiot lights and mechanics (1 Viewer)

[COLandCrusher]

So I bought my GX in April last year. During pre-purchase inspection the dealer said needed a few things including the OEM gas cap. So they reset lights, put on the cap and did a few other mechanical things.

A year later the lights come on (check eng, vsc trac control. etc...) I buy a new gas cap on ebay for about 15 bucks, and after about a week all the lights go off.

6 months later all the lights are on again. So I switch to the old gas cap, and after a couple days all the lights go off again.

month later, all the lights go back on. I take the car to the dealer for an oil change and they pull codes. P0430 and C1253 Bank 2 catalytic convrtr below thresh, and rec replacing hydro booster.

The car of course is running just fine. Other than the fact my fuel economy is like 11 MPG. So now the shop wants to replace the brake booster, and the catalytic converter. My main question is does anyone think that the Gas Cap is the culprit again? it clicks on, but soon as you undo it it breaks to be very loose immediately. Wondering do I just clear codes, replace gas cap and I should be fine? Or do I need a new catalytic converter? could that be causing poor fuel economy?

 

[The Great Him]

What does the code say.... They don't just throw random code out. I think your dealer was just full of it, yeah some times the code is for a gas cap, but typically it's because someone didn't put the cap on securely... Doesn't mean the cap needs to be replaced. A p0430 is a good sign of a bad o2 sensor. Ignore that long enough and you will be buying a new catalytic converter cause you have burned it up by running too rich or too lean.

Spend the money and buy your self a code reader for like $50 and pull the codes as soon as the light shows up and do the repair at that point.

 

[COLandCrusher]

So the decision was to replace the catalytic converter/exhaust on the front right side. Man I hope it isn't just an O2 sensor. Code P0430 Catalyst System Below Threshold Bank 2. Replace Exhaust Manifold $1100. My fuel economy sucks though -

 

[kbahus]

Did it fail Colorado emissions testing? Your poor mpg can be from all sorts of issues. Here is some info for you:P0420 wont leave me alone..

 

[BlackCat]

What does the code say.... They don't just throw random code out. I think your dealer was just full of it, yeah some times the code is for a gas cap, but typically it's because someone didn't put the cap on securely... Doesn't mean the cap needs to be replaced. A p0430 is a good sign of a bad o2 sensor. Ignore that long enough and you will be buying a new catalytic converter cause you have burned it up by running too rich or too lean.

Spend the money and buy your self a code reader for like $50 and pull the codes as soon as the light shows up and do the repair at that point.

Just an FYI, an bad 02 sensor won't ruin a cat. An A/F sensor, maybe , but an 02 sensor just monitors cat performance.

A gas cap will throw an EVAP code, like a PO442 or 445.