Cel ... P0171, P1153

[Nenad]

Hi everyone,

I would like to share my CEL experience here. Someone might find it useful, and also I would like to hear experts' opinion.

'99 RX300, 150K miles

The other day my CEL went on and I noticed the engine started running not so smooth. With further driving I noticed the engine starts trembleing, shuddering, when trying to go over 45-50mph, it shakes really bad, loosing power. Bad fumes (smell) at the exhaust and black smoke; actually not really black smoke, but it leaves the black mark on the concrete when parked in one place for a couple of minutes.

AutoZone pulled the codes for me, and it was P0171, P1153 and P0136 .

I read a lot of threads on this forum, and found that first and easiest thing to try is to clean the MAF sensor. I did that, using CRC spray. Unfortunately that didn't help.

Since I am not very experienced with car repairs, I thought it would cost me much more to start replacing the suspicious parts one by one, not really knowing which one is faulty. Also I really don't have the means and tools (and knowledge, I have to admit) to replace those hard to reach parts. Anything beyond the MAF and that easy accessible sensor (excuse my ignorance, I don't know which bank it is, but I'm talking about the one in front of the engine, little bit to the right - is it bank2 O2 or A/F ratio sensor ?)... I couldn't do it myself, so I decided to take it to the mechanic.

His diagnose is : replacing 6 plugs and one O2 sensor. I don't know which one right now, I'll ask about details when I go and pick up my car.

He quoted me $590 total. The parts (original, as he claims) are $340.

I would like to hear from you, for example, is it common for plugs and O2 sensor to fail at the same time? Basically, am I getting ripped off?

The repair is sort of expensive, but I think that most of it goes to the price for the sensor part, and that could be because he ordered the part directly from a dealer instead of maybe trying to get it on the internet cheaper (which naturally mechanic won't bother to do).

Thanks for reading and your potential input.

Nenad

[Nenad]

OK, so the repair was done, CEL off... but after 20-30 miles it came back on. Other than CEL, I don't notice any problems... engine runs OK I guess.

The sensor replaced was the Bank ? Sensor ?, the one in the front, easy to reach.

This time OBD pulled only one code - p0136, which is Bank 1 Sensor 2 (O2 sensor).

I have decided to try and replace this one myself. Where is this one located?

What is the best internet OEM parts source to buy this sensor?

thanks

[Nenad]

I called oxygensensors.com and they say bank 1 sensor 2 is the DOWNSTREAM one. So I ordered one for $103, free shipping. Let's see what happens next...

In the mean time my car sterted acting up again. It was riding fine these few days (with CEL still on), but this morning I noticed some shuddering (missfiring?) when accelerating on slight uphill.