check engine light, p0171 and p1130

[vdop69]

Alright, well driving on the way to school today my check engine light comes on. And I start to notice there is some engine vibration for about 1-2 sec when letting off the accelerator. After I get done with my final I go to autozone and check the codes...p0171 (system lean) and p1130 (front o2 sensor).

Suggestions?

[Dawgz]

for the cali spec cars (precat systems)

the front headre has a a/f Sensor, the rear header has a o2 sensor, and the sensor after the Cat is a o2 sensor.


U can do the swap to the OEM sensor, or if u know ur engine is running okay, u can get a o2 simulator TYPE B from URDUSA.com

The type B or "B" o2 simulator is for the cali spec toyota's

[vin888]

i have the same codes but dunno how to fix

[vdop69]

Normally if you have those codes you would need to replace the front o2 sensor which is on the exhaust manifold, if you have a 5sfe. But, in my case I did with aftermarket sensor, but still get the codes.

[vin888]

im also thinking for the california model. is it okey to buy aftermarket?
mine is 5sfe oem is quite pricey....

[vdop69]

Alright, well I replaced the air/fuel sensor with one from the dealer and I am still getting the p0171 and p1130 codes.

Any ideas?

[dc_98_cam]

Just guessing here ...
How is your gas miles per gallon doing?
Do you think that your injectors might be clogged or dirty ... not effectively spraying the gas into the cylinders? Ever changed fuel filter?

Diagnostic section, p.79, shows possible p0171 causes as:
Gas leakage on exhaust system

Air intake (loose hoses)

Fuel line pressure

Injector blockage

Manifold absolute pressure sensor

Engine coolant temp. sensor

A/F sensor

most likely .... injector, fuel pressure, MAP sensor, Engine coolant temp. sensor.

[vdop69]

Fuel filter hasnt been changed at least for 60k, bought it used.

I checked the air intake, no leaks visually.

How common are injector blockages?


could using bosch plugs and wires cause anything like this?

[vdop69]

Since my last post I have ran some injector cleaner, replaced the engine coolant sensor, and map sensor, replaced my weapon-r intake with the stock, replaced plugs and wires with NGK.

Still having the same issues.


I am starting to believe the issue is with a faulty injector or with my fuel system.

Any comments or suggestions? I am just about to bring it to a mechanic to get fixed

[dc_98_cam]

Originally Posted by vdop69

Since my last post I have ran some injector cleaner, replaced the engine coolant sensor, and map sensor, replaced my weapon-r intake with the stock, replaced plugs and wires with NGK.

Still having the same issues.


I am starting to believe the issue is with a faulty injector or with my fuel system.

Any comments or suggestions? I am just about to bring it to a mechanic to get fixed

When you let up on your accelerator pedal, the engine vacuum will increase ... If there is a loose vacuum hose, this might be drawing air into the intake venturi ... causing improper combustion ... loss of power. If you get a spray can of starter fluid, you can start the engine, and place a few judicious sprays of ether around the intake manifold, and also any vacuum hose, to try to find a leak, loose hose end, or other problem area.

[vdop69]

Originally Posted by dc_98_cam

When you let up on your accelerator pedal, the engine vacuum will increase ... If there is a loose vacuum hose, this might be drawing air into the intake venturi ... causing improper combustion ... loss of power. If you get a spray can of starter fluid, you can start the engine, and place a few judicious sprays of ether around the intake manifold, and also any vacuum hose, to try to find a leak, loose hose end, or other problem area.

Thanks for the reply. I was thinking air leak too, however, I had my mechanic check for any leaks and he found none. But I can check again tomorrow.

[dc_98_cam]

Originally Posted by vdop69

Thanks for the reply. I was thinking air leak too, however, I had my mechanic check for any leaks and he found none. But I can check again tomorrow.

Maybe then something to do with the vacuum ... like a vacuum servo valve..
The VSV for EGR is known to be a problem frequently ... probably due to carbon buildup from the EGR system ... This is also known to be a difficult part to test ... usually requiring replacement with a known good part.