We present the results of an analysis of data from XMM-Newton and CHANDRA observations of the high luminosity narrow-line quasar PG 1404+226 .
We confirm a strong soft X-ray excess in the X-ray spectrum and we find rapid variability ( a factor of two in about 5000 s ) .
When the X-ray spectrum is fit with a two component model which includes a power-law and a blackbody component , we find that low energy absorption lines are required to fit the data .
If we interpret these lines as due to highly ionized species of heavy elements in an outflowing accretion disk wind , an outflow velocity of \sim 26000 km s ^ { -1 } could be derived .
One interesting feature of the present observation is the possible detection of variability in the absorption features : the absorption lines are visible only when the source is bright .
From the upper limits of the equivalent widths ( EW ) of the absorption lines during the low flux states and also from the model independent pulse height ratios , we argue that the strength of absorption is lower during the low flux states .
This constraints the physical size of the absorbing medium within 100 Schwartzschild radius ( R _ { g } ) of the putative supermassive black hole .
We also find a marginal evidence for a correlation between the strength of the absorption line and the X-ray luminosity .