2001 Rx300 Engine Codes P0171, P0174, P1130, P1150

[kwilder]

I am new to the forum, but should have known about it years ago. My Lexus 2001 RX300 I purchased pre-owned at 73,000 miles (now 156,000) has been

nothing but repeated problems. These four codes I understand are sensors, etc. as I've been reading. However, I fear the transmission is going (again).

I am one of the unfortunate Lexus owners who replaced the tranny at 110,000 miles.

Here's what's wrong right now with the car, whether related to the codes, or entirely different problems. I really, greatly, enormously appreciate your

expert guidance and what parts (Denso whatever) I need to buy. I have a mechanic but he is not Lexus specifically trained. Can he do these fixes?

K - the car's problems:

Engine codes: P0171 System too lean Bank1

P0174 System too lean Bank2

P1130 Undefined code

P1150 Undefined code

Symptoms: While driving about 45 mpg, car started 'pulling' like it was not shifting right. Accelerated to 50 or so, felt like front of car started jumping.

Almost as if the wheels came off the ground (probably didn't, but in a panic, hard to grasp and describe what it was).

Mechanic friend came over, cleared codes. Drove the car next day - about 20-25 miles, the pulling back and forth started and all lights came on again. Cleared codes

and was able to drive to his garage (bout 6 miles). He cleaned a sensor (don't know which one, but on top of engine - plugged in and out). Checked all fluids, etc.

Now it's been only about 10 miles and shifting is wrong again. If I drive with O/D ON, is better. Am afraid to drive and damage tranny or anything more.

I have downloaded the articles from the host regarding these sensors, but is technical. I'm a female and not a mechanic.

How do I know which engine type I have in order to order correct sensors if that is what's needed? Can you tell me exactly what and where to order these from?

The vehicle has never has had a transmission fluid flush or change, differential fluid (change??) .

Lot in this post - I'll post other issues separately. Do you think my transmission is going again??? :( I pray not! Oh, and 'til I get this fixed, I'm without wheels. Pls help :)

Thank you! Kate

[PETER PAN]

GS300 with 85K miles had codes P0171 and P0174 in a 2001 enigne too lean bank 1 and bank 2. Car runs sluggish, wont pass smog test.

MAF resistance measured OK. MAF looks dirty. Spray clean with carburetor cleaner, but did not help.

Swapped in the same MAF from another Toyota. The P0171 and P0174 problem was fixed. Car runs smooth and powerful. Passed smog test.

[kdinh37]

I am new to the forum, but should have known about it years ago. My Lexus 2001 RX300 I purchased pre-owned at 73,000 miles (now 156,000) has been

nothing but repeated problems. These four codes I understand are sensors, etc. as I've been reading. However, I fear the transmission is going (again).

I am one of the unfortunate Lexus owners who replaced the tranny at 110,000 miles.

Here's what's wrong right now with the car, whether related to the codes, or entirely different problems. I really, greatly, enormously appreciate your

expert guidance and what parts (Denso whatever) I need to buy. I have a mechanic but he is not Lexus specifically trained. Can he do these fixes?

K - the car's problems:

Engine codes: P0171 System too lean Bank1

P0174 System too lean Bank2

P1130 Undefined code

P1150 Undefined code

Symptoms: While driving about 45 mpg, car started 'pulling' like it was not shifting right. Accelerated to 50 or so, felt like front of car started jumping.

Almost as if the wheels came off the ground (probably didn't, but in a panic, hard to grasp and describe what it was).

Mechanic friend came over, cleared codes. Drove the car next day - about 20-25 miles, the pulling back and forth started and all lights came on again. Cleared codes

and was able to drive to his garage (bout 6 miles). He cleaned a sensor (don't know which one, but on top of engine - plugged in and out). Checked all fluids, etc.

Now it's been only about 10 miles and shifting is wrong again. If I drive with O/D ON, is better. Am afraid to drive and damage tranny or anything more.

I have downloaded the articles from the host regarding these sensors, but is technical. I'm a female and not a mechanic.

How do I know which engine type I have in order to order correct sensors if that is what's needed? Can you tell me exactly what and where to order these from?

The vehicle has never has had a transmission fluid flush or change, differential fluid (change??) .

Lot in this post - I'll post other issues separately. Do you think my transmission is going again??? I pray not! Oh, and 'til I get this fixed, I'm without wheels. Pls help

Thank you! Kate

I am new to the forum, but should have known about it years ago. My Lexus 2001 RX300 I purchased pre-owned at 73,000 miles (now 156,000) has been

nothing but repeated problems. These four codes I understand are sensors, etc. as I've been reading. However, I fear the transmission is going (again).

I am one of the unfortunate Lexus owners who replaced the tranny at 110,000 miles.

Here's what's wrong right now with the car, whether related to the codes, or entirely different problems. I really, greatly, enormously appreciate your

expert guidance and what parts (Denso whatever) I need to buy. I have a mechanic but he is not Lexus specifically trained. Can he do these fixes?

K - the car's problems:

Engine codes: P0171 System too lean Bank1

P0174 System too lean Bank2

P1130 Undefined code

P1150 Undefined code

Symptoms: While driving about 45 mpg, car started 'pulling' like it was not shifting right. Accelerated to 50 or so, felt like front of car started jumping.

Almost as if the wheels came off the ground (probably didn't, but in a panic, hard to grasp and describe what it was).

Mechanic friend came over, cleared codes. Drove the car next day - about 20-25 miles, the pulling back and forth started and all lights came on again. Cleared codes

and was able to drive to his garage (bout 6 miles). He cleaned a sensor (don't know which one, but on top of engine - plugged in and out). Checked all fluids, etc.

Now it's been only about 10 miles and shifting is wrong again. If I drive with O/D ON, is better. Am afraid to drive and damage tranny or anything more.

I have downloaded the articles from the host regarding these sensors, but is technical. I'm a female and not a mechanic.

How do I know which engine type I have in order to order correct sensors if that is what's needed? Can you tell me exactly what and where to order these from?

The vehicle has never has had a transmission fluid flush or change, differential fluid (change??) .

Lot in this post - I'll post other issues separately. Do you think my transmission is going again??? I pray not! Oh, and 'til I get this fixed, I'm without wheels. Pls help

Thank you! Kate

Hi Kate,

Did you fix the problem?